License plate light rebuild?

Don't use anything too strong on that lens. You may melt it. Acetone will for sure, lacquer thinner might too. The paint might come off with soap, a scotchbrite, and a little elbow grease. Something else I find works good on most plastics is the Turtle Wax Chrome polish. You should be able to gently bend those tabs open enough to get the lens out. I'd then glass bead blast that housing and repaint with some good Rustoleum Professional aluminum color rattle can paint.