Pics might help, but if your hinges are like mine, you'll find plastic chrome strips on the back of the trailer side of the hinge, held on with double sided tape.
Strip them off and you'll see large phillips screw heads. Remove the screws and the hinge comes off the trailer. HOWEVER, I believe the nuts will fall inside the wall. There is an aluminum strip on the inside of the AS to the wall side of the door. If you remove it, I believe you have access to the inside of the wall there. I have heard others say you have to use a small hole saw to access the nuts under the strip. I'd look under here first before removing the screws.
I think you have to remove the inner door skins to get to the nuts for the door side of the hinge.
I would buff/sand them in place. Fabricate WOOD shields for the AS skin out of luan or other THIN solid material and tape them in place. That should protect the skin, even if you get unwieldy with the power tools. I would try a dremmel buffer wheel for the really tight spots.
Not an easy job, any way you look at it. I haven't done it yet, but I have been studying up and trying to muster the initiative. I'll bet it'll 4 - 5 hours each, minimum, just to prep them.
"If the women don't find you handsome, they should at least find you handy." - Red Green