Wash the headlight lens with car soap and water
Rinse and dry the lens completely
Mask off the paint and trim around the headlight
Apply toothpaste or a plastic headlight cleaner to the lens
Rub the lens with a microfiber cloth in small circular motions
Rinse off the residue and inspect the lens
Repeat if needed for heavy oxidation
Use a polishing compound for deeper haze or yellowing
Sand the lens with wet sandpaper if oxidation is severe
Start with a fine grit and keep the surface wet while sanding
Polish the lens after sanding until clear
Apply a UV sealant or headlight protectant
Let the protectant cure before driving
Clean the lenses regularly to prevent buildup