just paint over them. do a search for this subject on this board. Its a commonly asked question and you kind find good advice on how to paint them. if there is a glossy finish on them just need to wipe them down with a deglosser. then prime and paint with a semigloss enamel paint. make sure you have good ventilation because the oil based enamel will be pretty stinky for a day or so until it dries and airs out well. Good luck
LJ