I would like to paint the front bumper top and bottom plastic on my truck. By the way I have a 2004 chevy 3500 hd. I am not sure what type of sandpaper I sould use. My painter never did this so I am not sure. I just purchased a new top and lower and do not need to mess it up. Also what type of primmer or prep should be sprayed on before the factory color is applied. Any help out their. Thanks