URL: http://www.youtube.com/watch?v=kvFMFb9JylQ (EOS 50D)
URL: http://www.youtube.com/watch?v=O3cCTv7JbrY (EOS 1000D)
The procedures are shown clearly and it is carried out in a professional manner.
Besides, there is a guide for how to check and try to repair a Pentax MZ film body that had its mirror locked up in the following thread:-
http://forum.xitek.com/
