RV siding typically consists of sheets of aluminum, and the best method is often to replace them on an individual basis based on damage. Because of the size of the sheets involved, replacing them usually involves at least two people.
Use a screwdriver or crowbar to remove the frames on the sides and top of the siding. Remove any lights on the siding by prying open the lens and unscrewing the bulb. Use a flathead screwdriver or crowbar to remove the staples holding the metal sheet in place, and use a putty knife and hammer to separate the folded metal sheet from the RV at each corner of the siding.
Use a crowbar to remove all of the staples for the metal sheet you wish to replace, and ask another person to help remove the metal sheet as you do this. Use the old sheets to determine the size of the new sheet and the holes for lighting, and use a hole saw to cut out the holes for the lights. With your partner, lift the new sheet, and staple it exactly as the old sheet was stapled. Repeat this procedure for each metal sheet that needs replacement, screw the lights back in, and replace the lens. Use putty tape to reaffix the side and top frames.