Wash the headlight lens with car soap and water
Rinse and dry the lens completely
Mask off the paint around the headlight with painter’s tape
Apply headlight cleaner or plastic polish
Rub the lens with a microfiber cloth in circular motions
Use wet sanding with fine-grit sandpaper if oxidation is heavy
Sand with 1000-grit, then 1500-grit, then 2000-grit sandpaper
Keep the lens and sandpaper wet while sanding
Wipe away residue between sanding steps
Polish the lens again after sanding
Apply a UV sealant or headlight restoration coating
Let the sealant cure as directed
Repeat cleaning regularly to prevent buildup