Wash the headlight lens with soap and water
Dry the lens completely with a clean microfiber cloth
Spray WD-40 lightly onto the headlight surface
Let it sit for a few seconds
Wipe the lens with a clean microfiber cloth
Buff the surface until clear
Repeat if needed for better clarity
Remove any excess WD-40 from surrounding paint and trim
Wash the headlights again with soap and water after use if desired
Reapply as needed for temporary improvement