Easiest is simply using Scotch pads or nylon brush drill attachment… you choose the abrasion level. There is no need to scuff deeply, just scuff up the gloss. You don’t want to remove the paint entirely unless you plan to prime before applying the coating. No need to obtain a completely smooth finish, so some deeper scratches are not a problem. You will be applying a thick bedliner coating which will hide most imperfections.
Priming bare metal isn’t always required, but is recommended for a professional job with lasting results. Our coatings will adhere well to bare steel and many other metals, but are not specifically designed as primers.