Anyone knows how to replace the mirror on this camera?

Hi!

I've had this camera for almost 10 years and still in love with it. Now I'm using it for a personal/experimental project, and i need to modify the mirror of the camera. I tried to find manuals or tutorials of how to replace it, but couldn't find anything. If anyone could give me some tips around this matter would really appreciate it (I have a couple of bodies that I could use to get spare parts)

Thank you!

Joe