Yehaf,
It's pretty easy.. The bolt on the bottom of the bumper might require an extra set of hands(small hands) to install the speed nut in the belly of the sled. Its a nut that's built on a clip so the nut always stays in place for when you remove the bolt, hopefully the dealer already installed that? If I remember right we needed to drill a hole in the plastic piece that your dealer removed to allow for the bolt diameter. I think the directions tell you that you need to drill a hole in it, so again not sure why your dealer though it didn't belong there? I would have the 6 bolts on the sides very loose while you get the bottom bolt started that's the hard one. Once you got them all started snug them down and a few drops of blue lock tight on the threads is always a good idea. As far as the one the dealer striped your going to need to replace it, a nut/bolt supplier like Fastenal or at least a hardware store that should be able to match it up with something that would work.