there are three torx head screws, #15 size. it wont change your lighting adjustment at all by removing them. they are abs plastic so be careful pull them out, they sort of pop into position so pry gently.
i just painted mine black and its easy, i just used a green scotchbrite scrubby pad and some dawn dish liquid. rub lightly, this will remove any contaminants, i.e. bugs, grease, tar, etc. and scuff them lightly to accept paint.
i didnt use any adhesion promoter, just went right to paint. do about 4 coats with the first three just dusting to slowly build up coverage. give about 5-10 minutes between coats and the final coat do it slightly heavy so it looks wet but doesnt run.
i recommend using only flat paint and then clear coating if gloss is wanted but gloss paint will work too.
p.s. screw the screws into a piece of cardboard, doesnt have to be flush, then do a coat or two of paint from a top down position, it will get the exposed area of the screw head and not hit the threads.