There are a few options but the choice depends in the substrate. I’d try GooGone first. You can get it at supermarkets and hardware stores. It’s pretty benign on most surfaces but will hit the contact cement. Goof Off is good, too. Sometimes denatured alcohol is OK... but test first. Toluene irritates most contact cements and you can get them off using it, if you can find it. Lacquer thinner will dissolve the glue for sure, but it will hit most enamels and lacquers pretty hard. It MIGHT be OK on Imron or other urethane paints, depending on which one and how well cured, but lacquer thinner would still be at the far end of chemicals I’d try.