Rotel RMA-80 amp stopped working?

How should I go about getting this amp fixed? I think something internally needs to be replaced. For it while only one side was working, with either speaker being able to be connected, and now that side doesn't work either. Up until then it was working really well and I would very much prefer not to have to replace it. Would it be possible for me, someone who knows very little about audio equipment, to get advice on how to open it up and fix it myself, or am I looking at a very expensive shop consultation and repair? What is most likely needed to be replaced? Any advice is great appreciated!

Chamoogie
June 2010