OK - I finally made my way through this lens on my own. For future reference, here are the steps to CLA the late model, black, LTM J-12 lens:

Tools and materials used - precision slotted screwdrivers (will need a tiny one too), spanner wrench, grease.

1. Unscrew the rear cell and put aside in a safe place. Rubber to grip the sides will help with a stubborn cell.

2. Inner spanner slots on front, loosen and unscrew front cell.

3. Outer spanner slots on front, loosen and unscrew the aperture/front cell assembly. Watch for the spacer at the rear. This is where you would add/remove extension to adjust infinity focus.

3A. If you like, you can remove the aperture captive screw and unscrew the aperture selector. E.g. then you can soak the aperture in lighter fluid to get rid of oil on the blades. You can put some heavy damping grease in the threads of the aperture selector, but its never really a smooth mechanism on a cheap Soviet lens like this. (not like a prewar Zeiss Contax mount Biogon)

4. Focus ring - three set screws. Loosen, then slide focus ring towards front. It helps to mark the infinity marking on the barrel underneith.

5. Depth of field scale - one tiny set screw. Unscrew, towards the rear; may need to use spanner slot on the inner helical to get enough torque to get it off. If you put a spanner on the inner helical, use care not to damage the helical threads!

6. Remove infinity stop screw (the one toward the front)

7. Remove inner helical captive screw - note it has a different shape than the infinity stop screw. Mark which slot had this screw in it.

8. Separate the outer helical - make sure you mark the point of separation.

9. Separate the inner helical - mark the separation point.

I clean helicals by first removing as much old grease as possible with lighter fluid. Then I go over the helicals with concentrated dishwashing soap and a toothbrush. If there are rough spots when its reassembled (without any grease), then I go over the threads with #0000 steel wool, then dishwashing soap again. Once clean, I regrease with Schwinn synthetic bicycle grease. It provides a light action, and will not break down or migrate.

I find it easier to reassemble the outer helical first. Reinstall the infinity stop, then install the inner helical, then the inner helical captive screw. The inner helical will only reinstall one way correctly. Off one way, you'll never see the screw hole in the slot you marked. Off the other way, and you'll barely be able to focus before the inner helical binds. Do yourself a big favour and mark the helical separation points carefully

Reassemble by reversing steps 1-6.

I use a high-tech approach for cleaning optics - lint free kimwipes and windex. Blow the lens, clean with a windex wetted kimwipe, wipe dry with a dry kimwipe.

One more irritant I had - my helicals were, I thought, reassembled properly. My lens would only focus to 1.2m rather than 1.0m. Turns out after much fiddling, it was right! If your lens does this, remove the aperture selector captive screw, unscrew the aperture selector by one turn (making sure the dot is opposite the aperture numbers), reinstall the screw, then screw the aperture mechanism back into the barrel. What was happening was with the aperture selector screwed all the way in, it was bottoming-out in the lens barrel before hitting 1.0m.

I always check collimation on a good body using my Nikon FM2N SLR with AI 200/4 and a homemade focusing target. Its a glass microscope slide with scotch tape on the side closest to the lens, scribed "X" with a scalpal. I find the 200mm lens gives higher magnification of the "X".

Collimation on this lens was bang-on. Experience probably varies with Soviet stuff