I'd recommend getting a taillight or two from a junkyard to practice sanding and painting on.
Get a PBE store to mix up some base-black with clear, they can put it in a can. Also get some catalysed clear.
Don't skimp on the most important step: the prep werk, son!
For sure use a flexible sanding block, wet sand paper(900-1500), wax and grease remover, maybe even a clear adhesion promoter.
900 grit is good for taking off the pointless lettering, remember to sand in STRAIGHT LINES.
Patience is very important when it comes to wet sanding. Especially if you decide to color sand and polish the lenses once they're completed.
Something important I almost forgot- put duct tape over the the socket wholes while you're wetsanding.