For ordinary cleaning of plastic headlights, use mild soap when cleaning the car. If the headlights appear hazy or yellow, purchase and use a headlight cleaning kit.
Begin the restoring process after cleaning and drying the headlights. Mask the area around the light for protection. Most kits call for using sandpaper or other abrasive material when beginning the process. Use the abrasive to remove all the yellow and hazing from the plastic without scratching other finished surfaces on the car. Use the polishing kit to finish the plastic so it is no longer rough and dull. Apply the ultraviolet protector to the plastic to maintain the newly clean lights. Without the protector, the lights can appear hazy again within weeks.