To do it right....
I would say you would at least have to remove the rocker pin and the rear bolster pin. That way, you can open the knife completely and get to the 2 pins that hold the cover on.
I have seen one of Muskratman's videos where he shows how to install new covers without taking the knife apart. I have tried it and it does work. BUT, it does take some skill...... (and luck in my opinion). I would try it on my own stuff before I tried on another person's knife.
NOW, when I
recover a knife with a new set of scales, I take it completely apart. That way, I can completely clean it and make sure all parts fit back together well. I can also repair and weak areas. BUT.... that is for a knife with wear. Not a "like new" knife. That knife looks almost new.
I am sure Glenn will chime in because he does do a lot of work like you are describing.
The biggest thing like you have said above, is overcoming the fear of screwing up another person's knife. That is a fear I still live with. I don't trust myself with someone else's property. My fear is that I can not produce a result that will be pleasing to to the owner.
I hope to overcome that some day before I leave this earth.... BUT, until then, I just work on my stuff.... LOL.
NOW, I want to learn from some other mechanics!
"Life is tough.... but it's tougher if you're stupid."....John Wayne