Use power drill rotary sanding : ( KEEP IT MOVING ! Use lots of water - you are removing old dead plastic, so keep it wet and wash well between each sanding )
600 till evenly cloudy,
then 1500 starting to look clear again,
then 3000 looking pretty nice,
then Meguier's Plastx headlight polishing compound, looking OUTSTANDING !
then Xpel clear headlight covers. (
)
or Lamin-x (
)