I’ve got the same rear bumper without the tire carrier. Prep is everything. After you’ve sanded it, wipe down several times with a lint free cloth and alcohol. Prime with a self-etching primer if you are going to rattle can Topcoat. Give it very light coats (2-4) so you don’t create runs, especially around the cut out Warn emblem. Top coat after about 30 minutes 4-6 light coats. Should turn out very nice. Then touch up as needed in the future.
I can’t remember the size bolts you’ll need, but there are 4 for the crossmember on the ends that are easy to get to, 8 that are difficult to get to. I had to slightly lower my gas tank skid (2”) to get in there with all sorts of ball sockets, et al. If you’re comfortable dropping the whole gas tank it would be much easier. Lastly, if you’re going to tow with that receiver you’ll need someone to weld on some chain stays and you’d want some frame tie ins. I used Poison Spyder ($50). That makes it beefy enough to tow safely.
Nice find, a very nice bumper!