Hello all,

I've made this tutorial for a french forum and as pictures and Seiko lovers are the same world-wide ... I'm going to translate it the best I can. So please be indulgent as some technical terms may be wrong ;)

1.- Preface:

The goal is to try to answer most questions that are raised when someone plans to modify, or just disassemble his watch to change dial, hands or just remove a dust or correct an unalign chapter ring. I won't go as deep as disassemble the movement itself as my knowledge ends at the date rings level ... I'll try to help one to avoid most traps I've been facing when moding my own watches.

2.- Introduction:

The watch I'm going to customize is the well known SKX007 from Seiko. This is "THE" ISO Diver, 200m certified, screw down crown and back,etc, ... This is the model that comes in various flavors from Seiko itself and that has one of the biggest aftermarket parts catalog. I'm a real amateur, I can't compete with pros like Jake B or Yobokies, and that's not my goal. So the way I use to mod can be criticized (of course) and improved (for sure). During this tutorial I'm going to learn a Diver how to fly ...

3.- Dismantling:

Before starting, it's better to have the movement fully discharged, so hands should not move. Do not wear your watch for about 2 days and you should be fine with that point. Here are most of the tools I'll use during this customization. A case opener, hands remover and hands setter, casespring tool, dust blower, movement holders, crystal press, sharp knife, pliers, bench vice, ... and toothpicks !
Some "rodico paste" is as well useful to clean grease, oils, finger prints on dial, hands, etc, ...
All these tools can be bought on ebay for less than $100 for all of them. It won't be top quality tools but fair enough to mod/clean your watches as an amateur.

Let's start ! First, remove the bracelet using a case-spring tool or a knife or a thin screw-driver:

Now using a very thin and sharp blade, enter between the case and the bezel and apply a torsion on the blade. The bezel should "pop-out" quite easely:

Once the bezel dettached, remove the O-ring gasket inside it and the click ring which is located between the bezel and the case:

Something very important from now: Pack up your things !

Before going further, unscrew the crown and set it to position "2". Then move the hands to match noon (12:00 not 0:00). As it is dangerous for the movement to manualy move date/time during the automatic date shift, hands are placed at 12:00. Later on when setting back the new hands, it will be at 12:00 too in order to avoid an automatic date shift at 3PM ... and to avoid to take everything apart again. Once done, set back the crown in "0" position without screwing it.

Put the case, face down, in the vice, set your case opener to match the size of the notches on the case back and unscrew it. If it's the first time, it may be hard to unscrew it and easy to rip when forcing. So put some tape on the back to avoid to scratch it.

Put the opened case, face down, on your bench:

With a toothpick, vertically and softly press on the stem/crown release lever in the movement and gently pull off the stem/crown. It should come without forcing.

Pack the stem/crown and use the toothpick to extract the movement from the case. Take care of the hands on the opposite side, do not put the movement face down once removed from the case.

Keep the movement away from dust and from falling, outside of the case it becomes fragile:

Using the crystal press, push the crystal out of the case. Take care when choosing the size of the die, if it is too large it will push on the chapter ring instead of the crystal. Result is 50% chance to break the chapter ring when pressing ! Note that if you've not planed to replace the crystal or the chapter ring, this stage is not necessary. During the guide I'll use the same crystal and ring but I wanted to take pictures of all steps anyway. !

Here are the case, the crystal, the sealing gasket and the chapter ring separated:

And now what ? Pack up !

With an old toothbrush and some soap, clean up all metallic parts, it will remove dirt and old grease. Water and soap work for gaskets too, gently wash them with your fingers:

Get back to the movement now and use a movement older. Cut a thin plastic or paper sheet to make a dial protector. Slip it between the dial and the hour hands:

Use the "presto" hands remover to free the hands. All 3 hands are removed in a single step:

For the last step, use the toothpick to gently lift the dial to separate it from the movement:

Here you are !

I'm going a bit "deeper" than expected now as I want the date to be white on black instead of black on white for my mod. I have a spare "5" movement which is the same 7S26 used in the SKX with different date rings and a different plastic ring. This ring depends on the case so I have to switch them in order to use the "5" movement in the SKX:
And ...

It's done ...

I now have a SKX movement with date printed white on black !
As I don't know if this movement is set to "noon" as it was the case for the original one, I'm putting back the stem/crown in position "2" in order to move the hands. I've put a piece of tape on the rotor to avoid the movement to restart during the manipulations. Always lock the rotor on the opposite side of the crown, this way the release lever is still accessible and most fragile parts of the movement back are protected by the rotor:

In order to set the new movement to "noon" I use my hand setter to put back the original hour hand:

Using the crown, I check whenever the date changes and then I add 12 hours to it to match "noon" position. Then I use the rodico paste to remove all my greasy fingerprints.

Time to set the new dial. There's 2 feet under the dial that have to match the 2 holes in the plastic ring around the movement. Gently press the dial to the movement when feet are aligned. There's one thing to take care of if you order a custom dial, the crown position at 3.00 or 4:00. The SKX crown postion is 4:00 so order a dial that matches. If not, you'll need to remove the feet and position the dial by another mean or be OK to have at the end a watch with 12 at 1 o'clock ;)

Ok, the big part now. We start to set the hour hand. It's by far the easiest one. Axis diameter is quite large and positioning is not an issue. Set it at 12 o'clock using the hand setter. For all hands, you'll need to feel when it is correctly set. Not enough pressing and it will go lose, too much and it will break. My advice, find an old watch or buy some "parts for repair" on ebay and train until you feel confident enough:

Same player shoots again with the minute hand. This one is a little bit more fragile, axis is smaller too but positioning is still not a real issue. Once both are set, use the crown (still in position "2") to validated that hands have enough space to rotate without touching each other:

Here comes the most critical part for me. We need to put this very fragile, thin second hand ! Its axis is 0.2mm, positioning ... hazardous. Not easy to feel if it is correctly set. My advice, use a small piece of tape under the end of the hand in order to manipulate it easier attached to your index by the tape.

Good job ! All 3 hands are in place, let's check once more if they're not touching each other during rotation:

Last checks, date is aligned with the dial, it switches correctly, we're fine then !

Ok, the original chapter ring looks cool with the new dial and hands, it will be reused in the mod:

Use the rodico if you need to clean up the dial or the hands and store the movement in a safe place. Regarding the chapter ring placement, there's a notch at 12'o in the case. If your ring is original or plastic aftermarket, a corresponding stud (correct translation?) should be present. But with metallic and some plastic rings, no stud is present, you'll need to use a very small point of glue or tape to fix the ring in the correct position. If not, it may happened that the ring is turning in its place ... not good at all !

Put the ring in place it the case, then the sealing gasket (no grease here!):

Position the crystal on top of the assembly under the press:

Slowly press the crystal in the case. Take care of the gasket, if the crystal moves, the gasket can fold and eventually break:

We now have two set of parts ready to be mounted together:

Remove the stem for the last time, remove as well the tape on the rotor:

Put silicon grease on the crown's gasket:

Put the movement in the case starting where the stem tube is located in the case. Once in place, insert the stem/crown (whenever you insert or remove the steam/crown you need to push on the release lever on the movement, NEVER force it!). Then put back the case gasket with some grease too:

You just need to screw down the case-back manually, no need to use the case opener tool yet.

5.- Finishing:

As I want this mod to looks like an "aviator", let's use a nice silicon strap with white stitching with a clasp. This way it'll still be compliant with water activities.

Now I can firmly screw the case back:

Hmm ... missing something ... Oh yeah, the bezel !
Some grease on the bezel o'ring:

Little surprise for the end, a nice machined bezel to replace the "too much diver" original one ! Here we go ! Hard to believe it's the same watch at some point ...

6.- Bonus:

Let's call it SKY007 now ;)

7.- Credits:

didboulogne: For selling me is watch
Harold (Yobokies): For minute and hour hands
Jake B (10 Watches): For "5" movement, dial and second hand
Dave Murphy (PMWF): For his great machined bezel
Ebay: Strap

Thanks for reading :)