100% acetone nail polish remover. Mine's made by Onyx Professional. It's a lot stronger than regular nail polish remover and labeled as "maximum strength" and "Used by Professionals". You can find it in regular stores if you look (got mine at a RiteAid). I tried regular nail polish but it seemed to take a lot of time and scrubbing. This stuff melts symbols off in seconds. Just use a couple Q-tip with a very small amount of the remover and keep the cap on inbetween q-tip dips to lessen vapers (yeah, it stinks a LOT). Use gloves if you're worried about getting it on your hands (though if you're careful you shouldn't have to worry about it) and wash your pony very carefully when you're done.