Overspray problem needing solution

[nasqar]

My C10 has side marker lights with the two lights and the black base to them, I was told these were the "deluxe" lights. The problem I have is throughout the years no one has ever cleaned off the overspray on these or the tail lights or any of chrome moldings.

What is the easiest way to remove this problem without damaging the items? Any help would be appreciated. I was afraid that if I just took paint thinner, it may harm the lights or other pieces.