Presumably you are going to remove the bezel from the watch?
If you've got an ultrasonic cleaner, soapy water will normally do the job. If not, acetone will remove just about any paint, as will Nitromors.
If you plan on leaving the bezel in situ, try sharpening the end of a cocktail stick and just repeatedly rubbing the paint. The friction will soften and lift the paint, and you shouldn't mark the bezel.