1. Clean the parts that need to be repaired at the black plastic part of the bumper with water;
2. After the sandpaper is soaked in water, the parts with burrs that have been scraped will be polished until smooth;
3. After grinding, wipe the repaired part with a dry cloth or paper towel;
4. Stick tape around the repaired place to avoid getting it to other places;
5. Use a sponge dipped in wax to wipe the scratches in circular motions until the scratches are removed.