A light paint thinners will work.
My Y84 had many pieces spray painted in vinyl tan paint that weren't orignally painted. That came off very easily with thinners. Do not get the strong stuff you use to take paint off metal, just the cheapest off the shelf stuff. I have a specially made formula mixed locally that isn't as potent, and works very well on interior plastics. I use it to also remove the sealants off kick panels. General purpose off the shelf should really be able to do the trick, just don't rub it in too hard!