Revell 39617 enamel paint remover works pretty well and a lot of hobby stores have it, but first try it out on a non-visible spot. While it doesn't necessarily eat plastics, it can soften them up a little bit while it's doing its thing, so don't apply too much pressure while applying it. Other model paint brands also make similar paint strippers that are plastic safe.
What also works for some paints is chloroxylenol-based detergents/disinfectants (Dettol for example), never tried it myself but seen quite a few folks mention it in the past.