what you need to do (I don't believe in buyin kits for this stuff)
-sanding block (like Meguiar's foam sanding pad)
-1200 grit wet sand paper
-1500 grit wet sand paper (this steps should be done if you are not familiar with wet sanding)
-2000 grit wet sand paper
-3000 grit wet sand paper (this step can me skipped if you have a machine to compound the scratches out with)
-rubbing compound (3M makes ones that available in a lot of stores, Meguiar;s M105, Menzerna SIP also would work here)
-also a polish like Meguiar's M205 or a cleaner wax
-rotary or dual action polisher, if you have neither then get some foam application pads (not the cotton ones, as the foam ones have a little more bite)
-Wash your headlights well
-Might be a good idea to claybar them to get any dirt off completely
-Tape area around the headlights like this:
-Start wet-sanding. Remember to soak your paper for at least 15 min prior to use (the longer you can soak it the better), Use a drop of soap in your water bucket where you are soaking the paper. Spray your head light down with water and a little soap and the start sanding. You don't have to press hard, let the sand paper do your work for you. If you are using different grits of paper, remember every grit should be used in a different direction (use the 1200 in an up/down motion, the 1500 in a side to side motion, etc.). Remember to clean your headlight after every couple passes to make sure you are sanding evenly and not missing spots.
-When done sanding clean the headlights well again. Get some of your compound and go to town removing your scratches.
-Finish with a nice polish and or cleaner wax.