Hmm I'd say use blue painter's tape to protect the edges of the painted surface, but the design of the wheels is too intricate to do that. I'd take my time and use very little metal polish on the pad, so if you do accidentally wipe it on the painted part, it isn't a significant amount and would be easier to wipe off quickly. I don't know if it will damage the paint but it's better to play on the safe side.