light sand paper 2000 grit or higher. Wet or dry don't matter. Sand out all the flakes make it nice and smooth. Take a clean wet cloth and wipe it down and take a clean dry cloth and dry it really well. Then get a can of clear coat ( as far as I know Duplicolor is the best) do a Few light coats from like 8 inches away so the clear coat wont bubble or run. thats the way I do it and it's turned out pretty well.
Wet sanding is recommended and it does matter. After wet sanding, you should polish them with a headlight restore kit such as the Meguairs plastix. Clear coating the headlights is also optional and will contribute to the longevity of the clearness.
