Go to any hardware dept., get some epoxy that comes in a stick the size of cigar. Tear off a piece big enough to cover your hole, rub it together and after it is mixed, push it into the hole. Wet your finger and smooth it out the best you can. Wait 15 minutes and it will be hard enough to sand it smooth. Get a sheet of paper, cut a hole to match the patch size, spray paint it white. If not smooth enough for you, sand and paint till you love it.