I've found that acitone works great for removing most paints. But be careful, if used on the wrong kind of plastic it can melt or warp the plastic. I suggest using small amounts on a Q-tip and testing them on the bottom of the figures foot or somewhere where it doesn't matter before you get started. You can also carefully sand off paint but that is a real pain so I'd only do that if I had no other options.
You'll be lucky if you're one of the few to find someone who can tolerate you.