Yours looks a little bit different from ours but for the wall panels we had to grind rivets then remove windows then remove horizontal ribs on the exterior in order to pry the panel out of the space between exterior and interior walls. Not sure if that makes sense but it was way more complicated than we initially thought.
As for those seat tracks, we removed ours to expose the metal subfloor to properly assess rust. In order to remove those we had to grind off the heads of the bolts using a diamond wheel on angle grnder and then punched out the rest of the bolt. Went through 3 wheels but finally got them up.