[rohrmann]

You may have some screws break when trying to remove them, but, unless you have been running in very corrosive areas, say with salted roads, most should come out. When I had to repair a leaky gray tank, I had the entire front belly coroplast removed, and when I put it back on, I had a sufficient amount of new screws and washers to replace all of them, and did not use stainless screws either. I also installed additional braces, not so much to support the coroplast, but to support the tanks. I used 1 1/2" X 1 1/2" angle iron from a hardware store and attached them with the same screws. You could also, prior to replacing a screw in an existing hole, add some anti seize compound to the screw threads, and if installing a new screw in a new position, install the screw, then back it out and apply the compound. Prior to installing the extra braces, and after cutting them and drilling holes for the screws, I painted them with a good spray paint designed to prevent rust. I used my heavy duty battery powered drill with a nut driver for this work. A light duty drill may not have enough power. It may help to drill a hole slightly smaller than what the drill bit pilot part of the screw would drill, but I found that was not needed. You could also spray the same paint on all the screw heads once the work is complete, too.