Well now you need to replace them.
Go to a scrap yead and get 2 new lenses and fit them yourself. That is the cheapest option. Restoration is out of the question. Scratched and opaque light covers will not pass an MOT.
They can be restored, If not replace them
You might be able to save them but it will be a lot of work. Sand down with progressively finer grades doen to 1800 or 2000, then rub with t-cut. T-cut can also clear up faded yellow headlight lenses.
Good luck!
Too late. They sell graffiti remover at paint supply houses for $15 in a spray bottle. You just wipe/rub it off with a terry cloth towel.
New ones needed
I got primer dust on the rear lights first first and then I sanded them and plastic is quite distorted looking.
