1. Before you jack your car up, be sure to loosen the lug nuts on the flat tire; you will not be able to loosen them once the tire is off the ground.
  2. Once you've loosened the lug nuts on the flat tire, get your car jack and raise the vehicle so that the flat tire is not touching the ground.
  3. Completely remove the loosened lug nuts from the flat tire. Then take the tire off its axle and put it aside.
  4. Put your spare tire on the axle where the flat tire used to be. Screw the lug nuts onto the new wheel until you cannot turn them anymore.
  5. Lower the car back down, so the new tire is touching the ground. Tighten the lug nuts once again; since the tire is held in place by the ground, you will be able to tighten them more than you could when the tire was off the ground. Make sure the lug nuts are screwed tight. Otherwise, you run the risk of your tire falling off while you're driving.
  6. Once you've done all this, place the car-jack, tire iron, and flat tire back in your car. Do not leave anything on the road or shoulder, as this would be a hazard.
  7. You're now ready to drive your car again with its newly changed wheel.