An old tutorial I've done two years ago with the precious help of Isthmus. Hope it will be usefull !
The following article is intended to instruct you on how to go about changing your own watch crystals on base model SKX divers (7s26-0020/9), on 7002 divers, and on a Sumo.
That post was kindly rewriting by Isthmus (Gabriel) for an easier understanding. Hope it will be useful!
You can do the same with sapphire glasses for SKX, 7002, SUMO etc. ! Parts Needed (Purchased from Jules Borel & Co.) for both SKX and 7002 divers:
- Généric crystals
- Crystal gaskets
- Caseback gaskets
- Crown gaskets
First, lets start with my SKX007J, which has a scratched Hardlex. Let's go replace the crystal with a new Hardlex.
- Start by removing the strap from the case (sorry, no pics),
- Put pieces of over the caseback notches so as to protect the case while opening it (masking tape works great for this):
- I usually put the watch case in a case vise. In this manner the case is protected from accidental scratching and is more easy to open using your caseback opening tool:
- Unscrew until the caseback is loose and then finish unscrewing it either with your fingers or a pin of wood:
- Your caseback should now be opened!
- No you’ll need to remove the caseback gasket:
- You will now need to remove the stem and crown. First unscrew the crown; then push the little lever on the plate and pull the crown all the way out. If you did it right, the crown and stem should pull out as a single unit without much resistance.
WARNING: when pressing the release lever, do so gently and not all the way down. If you press to hard you will release the movement’s keyless works and you will not be able to set the stem back in:
- No it’s time to remove the movement: By now you have removed everything that kept the movement in place, so it should go out easily. With a pin tool, simply lift the movement out of the case - consider blowing a little bit too to avoid dust getting into the works!
- With the movement out of the case, place the movement into a movement holder and under a dust-cover:
- With the movement safely tucked away, it is no time to remove the bezel. Your best tool will be a “good-ole” Swiss-Army knife! Just put the edge of the blade between the bezel and the case and twist. The bezel should pop right off.
- You are now ready to begin removing the crystal. First you’ll need to choose the correct press die to remove the old glass. Be careful to select the correct size die (you’ll see in a minute why):
-Now that your watch is in the press, press the crystal out gently and carefully. Why do you ask? Well because if you do as recommended, you just might avoid problems such as a broken chapter ring!
Why did the chapter ring break? Because we need to use small dies. This one was too large. With a smaller die there will be no problem.
You have no removed your old crystal and your old gasket and it is time to install the new replacements.
- Set the gasket into the case and set the crystal over it. With the press, press the crystal onto the gasket. Be careful though, in order for the crystal to fit perfectly, it should be fitted perfectly horizontal before being pressed in:
- Your new crystal has now been installed. To put the watch back together, wipe the interior of the crystal clean (until it is smudge free); blow the inside of the case to remove any debris; replace the movement back into the case (make sure to align the stem recess with the crown tube (if the alignment isn’t 100% perfect don’t worry, once you fit the stem back in place the movement will line itself up); Insert the stem and crown (If you didn’t release the keyless works, the stem should click and lock back into place);place the caseback gasket into it’s seat and apply a minute amount of silicone lube; and screw the caseback back in place (
WARNING – do not over tighten the caseback or you will deform the gasket and compromise water resistance).
The same, with the new hardlex and new chapter ring (genuine skx007):
NOW: Lets do the same job to a 7002-700j
The challenge: changing glass, crown-gasket and caseback-gasket:
The general instructions are essentially the same as above. This time, however, I chose the proper dies and managed to save my chapter ring. All success!
First, follow the instructions above to remove the old crystal, crystal-gasket and the chapter ring:
The case is cleaned:
New Hardlex properly fitted!
Stem and gaskets (old and new):
All is now in the right place. Follow instructions above for installing the caseback gasket and closing the caseback…
“et voila!”
Third: Installing a sapphire on a Sumo:
Keep in mind that you will need to source the sapphire crystal from an outside source, since they are not carried by the major supply houses. Ask the forum for sourcing recommendations.
Once again, you will need to follow the written instructions above.
Sorry, no more pics available... Only the watch ( selled, 
) with the sapphire: 
Thanks for watching guys. I hope this will be of help in the future.
Otherlife-san ( old outremer2) and Isthmus for rewriting
