Put the nut back on the wheel but leave a gap between the nut and the wheel. Then muscle up and press your back against the seat as hard as you can, planting your feet on the floorboard behind the brake pedal. Using both hands at 9 and 3 o'clock, pulll as hard as you can while rocking the wheel side to side. I have pulled many wheels this way when I didn't have a puller handy and it always has worked for me. Just be sure to put the nut back on first or you will be wearing the wheel around your neck when it breaks loose.