Was there ever a solution to this? I'm also trying to figure this part out as I work my way through a repaint on an M6 LHSA.
Hello!
Yes, pulled my MP apart to test this, and learned that the windows are taped down with a very thin line of black double sided tape around the edges of the windows holding them in place from the outside. To remove the windows I put the top plate under hot (ish) water for a few minutes to soften the tape but without shattering the glass - a heat gun used carefully would be better for this (but not so hot that the glass shatters)….
After heating, I just pushed very gently and carefully from INSIDE the top plate outwards, as in, the windows are taped in from the outside, not from the inside. They pop outwards, rather than inwards. BE CAREFUL DOING THIS, DO NOT CRACK YOUR WINDOWS!
Once removed, I was careful to keep the thin tape intact on the windows, and after I was done tinkering, simply stuck them back in using the same tape. This is a temporary measure, and once I have finished the repaint, I will probably try to replace with fresh tape before reassembling.
I have attached some images showing the direction the windows come out, you must put gentle pressure from inside the plate and push them outwards. Be careful and have fun! I will post this on the thread too.
http://www.pentax-manuals.com/manuals/service/leica_m2_service.pdf <---Link to Leica M2 service manual - some good info.
Hope this helps. Don't judge.