You won't find that in the Service Manual. The closest to it you could come would be the exploded diagrams of all the pieces that make up the body in the Spare Parts List, but there are no procedural descriptions there. You're asking about stuff any good body repair person would know, knowledge that comes from experience.

From my own experience I can say that most of the answers you seek become obvious when you actually go about taking something apart and putting it back together again. My body-related experience is in the realm of vintage VW, though, and not M-B.

You should ask your specific questions in the Bodywork DIY section of this site. Chances are there are other members of this forum who have been there and could possibly give you the direction you need.