I'm going to give this a shot at least on my passenger side light...I got my Mach HIDs used for $500 because the passenger side lamp has some heavy scratches on the side (as if the previous owner had a run in with a pole or another car.) I'll probably need to start with a rough sandpaper...800 grit or so on the bad part at least and work my way up from there. BTW, when you wet sand them do you just use water, or something else?
To take the lamp completely apart is a pretty complicated and risky procedure...from my understanding, you need to "bake" the housings in an oven at 200 degrees to get the plastic soft, and the use a knife and a heat gun and cut the clear lens off from the rest of the lamp, to be epoxied back on later. Its usually done to paint the chrome parts of the headlight black...if these headlights weren't so expensive to replace I'd do it to mine.