Fix a flat tire on a bicycle in three easy steps. First, use a screwdriver to pry the tire off the rim. Be careful not to poke another hole in the tire. Second, pull the inner tube out of the tire and patch it (the tube, not the tire), using a tire patch kit. Make sure you find the hole in the tube first. Third, stuff the tube back into the tire and put the tire back on the rim. Don't tear off the valve stem in your hurry to get back on the road. Remember to pump up the tire when you're finished.