Yeah, I know C#s have been covered to death everywhere, but one thing they seem to have missed on every website I've checked: how are the surrounds for the two viewfinder windows on the back attached? Are those pressed fittings or do they screw out?
They are pressed in, I remove the lens glass and then use a small socket over a larger socket, couple of light taps, done. If you have never removed the lens glass there is a small ring holding it in.