Best bet is to see if it will come away using a blunt knife. If not, a cotton wool ball dampened in paint remover will be best. VER SPAINGLY though so as not to let it get into the edges.
Baby wet wipes are also brilliant for removing old paint. They have oil in them which seems to penetrate the old paint, making it easy to move. Rub the paint gently with the wet wipe for a wee while and then put a little pressure on the wet wipe with your nail and the paint should come off fairly easily.