BMW F800GS Headlight Restoration: Fixing Cloudy or Yellowed Lenses tresseslength.com

Begin by washing the lens with mild soap and water to remove dirt and bug residue. Mask the surrounding fairing and painted surfaces with painter’s tape so you do not accidentally sand them. The core of the job is wet-sanding: start with around 600-grit sandpaper and work progressively through 800, 1500, 2000, and ideally 3000 grit. Keep the paper wet at all times and sand in alternating directions between grits so you can see when the previous scratches are gone. The lens will look uniformly frosty when you are finished sanding, which is normal.