get some 1200 grit wet sand papre, peppys has it, some prep spray, your tint the clear. and rubbing compound.
remove it from the car, wash it, then wet sand with warm soapy water, dry it off, tape it off if need be the back edges not sure what it looks like, you may not need to tape it off.
set your light up so its in a way you dont have to move it to paint it. spray the edges first, then 50% over lap with each pass, so for a 3 inch light bar two passes will be one coat. keep the can the same distance from the part, and keep the same speed as well.
let it dry 10 minutes or what ever the can says, and repeat till its dark enough for your taste, 2 coats is see through still 3 will black it out good.
once your tint is on let it dry the wait time, then clear coat it as per the cans directions. let it dry for at least 24 hours, then wet sand again with the 1200 grit paper with warm soapy water till its smooth, then your gonna buff the fine scratches out with the compound. and its done.
edit: the prep spray, after you wet sand the light, and mask it off if need be, then hit it with the prep spray, this will remove all your greasy finger prints. then start to tint. and so on.
