They send out instructions that go something like this. First clean the stock with a degreaser ( I use alcohol) to remove any mold release agent. Second sand off any remaining mold lines ( the ones I've used had very faint ones). Third sand the entire stock and degrease again, then apply lightweight auto body filler to fill any voids in the stock. Sand off the filler to a smooth finish then prime . At this point I mount the recoil pad using epoxy and grind it to fit the stock (I like Pachmayr old english pads). Then lastly paint and clearcoat ( I use a very hard textured paint and clear coat and over several seasons have not needed to touch up any stocks).