My shell Eagle it was easy to remove the driver side panel. It was screwed on on the top edge and front and back edge, and airgun stapled into the aluminum tubing along the bottom edge. It was also under the support board for the overhead pull out bed which had to be removed. No fasteners for the panel except on the edges. The screws were visible and easy to remove, most of the staples were not visible and I had to carefully pry the bottom edge off, mostly pulling the staples through the panel which came off in one piece. I'll be reattaching only part of it back as a lot of the wall will have appliances, cabinets and such like against it. Won't use staples into the aluminum, it looks like each of the staples created a potential fatigue crack start location. Only use stainless steel screws, of which #6 or #8 are probably the appropriate size. Any of the original staples I run across I'm replacing as they are galvanized and many of them are rusting after only 5 years. For the most part I prefer screws in case I need to go back in again, but any staples I use will be stainless steel.
The rear panel on mine is under the lift system at the top, don't plan to take it off as only a little wiring to put in there and removing a lift panel and putting it back is significant work. Passenger side wall would require removing the window and overhead bed support. Again don't yet have justification for removing that wall yet. I'd have to remove the front sliding window to get the front off. Do want to trace the main wire into the camper there, though I have no plans to use that hookup and will put the hookup on the driver's side, which matches the wiring of my Ranger better.
The shell did not have much wiring, and little or none of that will be reused in my work. I'll be putting in a better grade of marine wire. And as much as possible making it more accessible for future repairs/modifications.