How to remove VHT Nite Shades paint?

My friend has a '91 Toyota Cressida and he sprayed his tail lights with VHT Nite Shades so the tail lights are completely black. Well, he got a ticket for having them too black and now he wants to remove the paint. I was thinking maybe paint thinner would take it off? any other suggestions?

maybe acetone? i would be careful to make sure it doesn't mess up the lenses though.

I would not touch those lenses with any kind of solvent. Your best bet is to sand off the paint with progressively finer sandpaper, start with 400 grit and work your way to about 1500 grit. When you get to 1500 grit you may want to start wet sanding so the paper doesn't clog too fast. When then lens feels uniformly smooth buff it out with an automotive compound or a metal polish, Mothers cream metal polish shoulod work very well in this application. This is a lot of work. It will restore the look of the tail light. If the parts for this car were not expensive and few and far between, I would say just replace the lenses.