When you dis assemble the headlight, there will be the chrome housing. This is what your sanding. You won't be able to get all the chrome off, but just do your best and sand away. Just go to your local Kragen's or autoparts store, and buy 600 grit sand paper. A few sheets is more than enough, the sanding down isnt too important. And yeah, one bottle of spray paint will last both headlight housings. I used one bottle to do my headlights, and then my emblems.
I'm planning on purchasing the spray paint and grit on amazon :].
You know any local store with Krylon paint? Or amazon is the only hope?
double checking is this the same product you use? (paint)
http://www.amazon.com/Inch-Hook-Sand...865606-2667203 (sandpaper) or http://www.amazon.com/Magnate-V616G6...870&sr=1-(sand paper)