I did this in 3 parts but I wanted it in one place.  So I merged them here.  People have asked what is involved in modifying these 1675s so I just snapped some pics whilst I did the disassembly. I'll do the same with the other steps. To start, our subject:     Hands are set to 12 to make it easier to remove later. Sticky ball or its like to get the back off.     Blue screwdriver to remove the rotor.     Same screwdriver to remove movement holding screws     On most 21js I use the red screwdriver to avoid pressing too far and screwing the keyless, but on this gmt movement you need something smaller. I use a very small screwdriver or pin tool. Pull the crown gently while pressing the release lever very slowly. The stem will pop out and quit pressing. The key is touch. You don't want to be looking for a tutorial to rebuild a keyless.     Its out.     With the watch face side down place the cushion over the back and flip it over, letting the movement clear the case.     Put the stem back in the movement. On this movement I find it impossible to do this unless I lightly depress the release button, and gently insert the stem. A bit of a twist of the stem will help too. Put the movement in a holder and store the movement spacer. I generally use the yellow hand puller for removing hands. I made the dial protector out of a business card. Slide the card under the handset being careful not to damage indices. The position the protector so the feet of the puller won't damage the dial, Squeeze and the hands pop off. Sometimes I use the levers to ease a hand off. You really need the levers when the sec hand is already off, because the puller would likely damage the pinion.     Oh hell, I popped off one of the indices when I put the "protector" on. No biggie, spot of glue and place it back on the dial.     This is why the cartel dials suck. They use indices instead of painting the lume on. SUCK, SUCK, SUCK. There are ways of making it acceptable but no way to make it stellar other than buying a dial that costs as much as this watch. See how they are raised?     There is also a dial holding screw at 6 and 11. Unscrew those a bit and you can take off the dial. Be careful not to lose the gmt pieces, especially the tension ring (little brass bent washer).       Now to disassemble the bezel and plexi from the case. This is where lots of people screw up. You have to very carefully ease the bezel assembly off using both a razor blade and a case knife. If you don't do it very evenly you will destroy the plastic gasket that secures the bezel assembly to the plexi.     Case knife to ease it up a bit more.     And poof, off safely ( I screwed the gasket on the first one I did cause I didn't know it was there). If you do mess it up you can order a replacement from a watch supplier but it took me many tries to find one that actually fit. Don't screw it up.   Run a case knife under the bezel insert from the inside of the bezel assembly. It is held on by double sided tape and will come off easily.     I'm going to be using files around the crown guards so I'm taking out the tube. I use a 4 sided file to take it out. First I tease out the oring inside the tube and then put the file in and rotate counterclockwise. Usually backs out without incident.     Everything neatly stored away until the next step.     OK so as I said in the last part the dial on these really lets you down.     It is flat and cheap looking with applied indices. I want to add some texture and I want to relume the dial. Reluming a dial like this is really hard, there are no convenient circles to apply the lume to. Nothing to draw your eye away either. The lume on these is usually apply like a screen print or ink jet type machine. Will be hard to achieve something good, but this watch is about $125 and a dial on ebay or Yuki is $125 and up. We will try to overcome.   So we start with a unevenly applied coat of matt lacquer. I want it to look like leather at high mag, it won't on the watch. These pics are macro so they will look a bit extreme.     Now you could put on another couple coats of lacquer and it would build up around the indices and meld it into the dial. That looks better. You could take some coffee or watercolors and, depending on your desire to age it, get something eventually like this.     And that looks ok. But lets take off the indices by pushing them out from the back with a pin. Very carefully because you can lift the paint on the dial.     Now we've got a template for the lume. The slight build up of the lacquer shows me where to lume. It is still hard to do.   Here is my lume stuff.     I use a water based lume binder for two reasons. First I can use watercolors to color my lume and match anything pretty well. Second I screw up, and the water based stuff I can wipe off with those manicurist Qtips you see there. I can't tell you how to lume. You have to screw up stuff for a while till you get better at it. Start with something like this, it is easier.     It doesn't have to be perfect, you see some godawful stuff on gens on ebay. So I applly lume with oilers. You can watch some really good people do it on youtube. So after an hour or so I get here.     Remember you are still looking at high mag pics. It will look way better on the watch. I let that dry real good, at least overnight. I will sand the lume where I can to make it more even (cause I'm not a master). I cut manicure emery boards into tiny files to work on that lume. I'm ready to put the hands on. BTW I relumed them to match as well. I've got brass tweezers so as not to scratch the hands, a hand set tool, a ball point pen refill (sets hour and gmt hand). I put the gmt hand on and rotate it around the dial to make sure it doesn't foul on the indices. I had to sand some of them down a tiny bit.     Tiny GMT hand - expensive little trick     With the hands off I advance the watch till the date just snaps over. Now I will attach all the hands for midnight.     Now they are all on.       In sunlight, I still may clean up a bit around 6/9/12.       OK, so next up is drilling and reshaping the case. Let's do the case. Drill press first with 1.3mm bits. Use cutting fluid and good bits, 700 rpm or thereabouts.     Holes done.     Work on the CGs. You can find an infinite number of different gen CGs on the web. Makes you wonder what they actually look like in the wild. So do what you like. These need to be thinner and a bit more sloped.     with this     and these     OK, like this rough shape better.     So I sand this with 220, the 500, then wet sand with 1200. Finally I polish with this.     OK so now lets go to assembly     If you are reusing the original stuff, then just carefully reassemble it. Don't mangle the plastic gasket.   I'm using a Clark bezel assembly, insert and plexi. That runs about $100. You may have to sand the plexi a bit to make this fit. Sometimes I do, sometimes not.   Put the tube back in with loctite blue.   put the plexi on, retaining ring on.     Press it on     After you have the retaining ring on, you can put the tension spring on and snap on the bezel.   Movement onto movement ring, then flip over into case.           Put the stem in. You will have to depress the stem release button to put the stem in. Put the movement holders and screws back in. Use silicon grease on the gasket and screw the caseback on.     OK we got a watch.     Insert won't snap in, I use double sided tape to put it on. Surprisingly the Clark insert WILL snap into the cartel bezel assembly, no tape required.     You will have to mod the bracelet to fit. You can use a dremel with burr bits to ream it out to fit the new 2mm spring bars.   Sooooo.........             A few pics with an unaltered 1675. You can see the differences in the case and CGs.             And that's it. Let me know if I left anything out!