My coach came with an aftermarket ladder. This is not a genuine GMC ladder. It has 3 attaching points. 1 at the bottom, 1 directly under the rear window and one on the roof. Here is what Jim Bounds has to say about reinstalling. \"Originally, the ladder was simply screwed into the plastic body, that didn\'t do too bad but it was always a source for leaks and corn fed guys would tax the screws ability to not strip out. We still use that system on the roof (cut the hole and seal it will under the rack footprint-- use SS #10 sheet metal screws), on the top supports above the rear window (the screws have to deal with the rear panel seal and a pieces of steel bedded into the plastic at the top. The brackets on the back will hold better with well nuts. You cut a 3/8\" hole, slip in the rubber well nut (the same thing thats used in the holding tanks for the new system sender pickups) and tightn is snug (not torque tight)\" If powder coated you may use a hone on the step holes to clear the pipe.