Rebuilding Power Amplifier(s)

I have a couple of Metaxas Solitaire power amplifiers.
One amp is operating on both channels and the other has only one channel working.
They have been inspected by a repairer , who has refused to conduct any repairs as repair work has previously been conducted to a poor quality.
So I have now retrieved them and propose to refurbish myself.
- Its either that or just dispose of them.
My plan is to replace every discrete component  to original spec or better .
Now I have no experience of such work , but I can't see any great skill needed for such work.
Have I under estimated , not the quantity of work as I have plenty of time , but the complexity for a novice.
I'm interested in comments.