Here is what you could do. Spray paints are not very tough (compared to stuff like Duracoat and Cerakote), so alcohol and mineral spirits can remove them. I would try rubbing alcohol (preferably 91%), and use a rag first and see how the plastic reacts. If the paint comes off, keep doing it, but be patient, and the plastic can be very sensitive, also mineral spirits may not affect the plastic too much. To save time though, you can just hit it with a scotch-pad until it is even, but roughed up, and spray whatever color you want over it. Hope this helps.