i'd imagine if they are black... and only painted black... you will still need to to sand them down. its gonna be a pain because going from black to white has issues anyways (moreso than any color to black) but you are going to want to sand the clearcoat off at least because the paint will flake off sooner if you dont. if you wanna do it right and only have to do it once... take a lot of time to prep the wheels, sanding, cleaning, primering, painting and so forth. goodluck.
chile