I used sandpaper to roughen up the grill.
Wiped it down with rubbing alcohol.
Sprayed it down with a primer.
Sanded the primer and resprayed.
Bought the rattle 3R3 paint online( sidenote)
I did mine outside, and was too humid. I advise that you have a cool place to prime and spray, I used a red primer. That way if it gets scratched it will not be as visible.