If you have a plastic part that has become badly scratched, you can repair it in a few easy steps. You can find the materials needed for this project at any automotive supply store.
Wash the piece of plastic thoroughly.
Sand the entire surface of the plastic, not just the scratched portion. Begin with the lowest numbered grit on the sandpaper, and move up to higher numbers (finer grits) as the scratch becomes less deep.
Wash the plastic again to remove debris left from sanding when the surface is smooth again.
Apply the plastic polish to both the polishing cloth and the plastic.
Polish the surface of the plastic until it attains a glossy finish. Your scratch will now be repaired.