Are you talking about the rear bumper protector?
I understand from other forum members it's supplied with 3M automotive adhesive tape. Usually all you do is clean the surface with a non-oil based cleaner (I use non-chlorinated brake parts cleaner) and apply. No sanding or scuffing of the paint required.
There is another recent post about this:
zerothread/338447
Now to avoid nicking the bumper when hooking up a trailer, I use a 12x12" piece of 1/2 plywood that is notched to fit partway around the ball platform. It's saved me a few times already.