Cross post from FMForum;
I have yet to do this on the Zeiss 100/2 MP, but I can't imagine it to be very different...
OK, so I just decided to wing it, and it worked.
The Distagon is easy to disassemble, and most of the hardest parts can be avoided completely for this fix.
I did it the long way, removing the mount, the mount's baffle, the CPU, the aperture ring (and its tiny click ball)...
The short and easy way is to simply remove the mount screws (careful, there are extremely thin washers/shims between the mount and the lens. They are important and they look like they can be damaged by just looking at them!)
Once the mount is removed one can see 4 screws, marked with red circles below. Note, the image shows how the lens looks like with the aperture ring, etc removed.
Loosen these 4 screws and the whole DOF scale ring, with aperture ring, will come off from the lens barrel.
You'll probably notice some infinity adjustment shims ( I had two, one thick and one thin). Remove these carefully as they are thin and susceptible to dirt. Under these shims are 2 copper helicoid guides. They are each held in place by two screws. Mine weren't particularly tight. I tightened these screws, assembled the lens, and the wobble/play problem was solved.