The best thing and eaiest is to use some Acetone (dimethyl ketone) with a rag. The acetone is a ketone and will remove most paints. Toluene (methyl benzene) will also work, but not quite as good as acetone. All you need to do is soak a rag and start rubbing. Just remember to ware latex gloves with the acetone or nitrile gloves with the toluene. I work as a chemsit at a research lab facility and this is how I know this. It should be no prob and good luck.

PS: The acetone and toluene can be bought at most hardware stores like LOWES or HOME DEPOT. Also the gloves can be bought there as well.

PSS: Just out of couriosity, why do you want to do that anyway???