the clear coat is what makes paint shine. You can do this one of two ways. You can 1, simply degrease and scrub the rims and allow them to dry for atleast an hour or so , mask off the tires and then put on light coats of whatever color you chose(flatblack im assuming?) Do that for a few coats until its done perfect. If you have never painted anything before, take your time and put on light coats, allowing it to dry for a bit before putting on another coat. Try to do it in a clean area as well...as long as you take your time and do it right, you shouldnt have any problems. This is the easier route...usually at the shop we will sand them down with a fine sandpaper first, before the scrub and then let it dry then primer it. I guess it depends on how picky you are about details. The paint shouldnt chip as long as you arent using a hard-brisle brush...i personally use a seperate foam wash mit, they work best for not scratching wheels. I hope this works out for you and let us know how it turns out.