*NOTE DONT TRUST ME ON THIS IM APPLYING WHAT I DO TO INTERIOR PIECES TO YOUR JOB*

ANyways i would guess sand it down....primer,sand again,apply the paint, sand, paint,sand,paint,sand,clear coat, sand,clear,sand,clear,then sand and smooth out...oh yes keep clean before painting...and dont wash for a while so paint can cure after job is done

again im not sure...when i painted my bumper it was spray painted :P lol im redoing it this coming up weekend though...