If it wasn't paint formulated to stick to plastic you might be able to warm it with a hair dryer and get it to loosen up. There are some "green" paint strippers that might be tame enough to strip the paint without harming the plastic. It should say on the label.

Save a life, adopt a senior shelter pet.
The three main causes of blindness: Cataracts, Politics, Religion.
Name your dog Naked so you can walk Naked in the park.