You hit a curb or run over a sharp piece of metal, or maybe your tires just don’t have enough air in them to go on.

Step1: Apply the parking brake, and for manual transmission vehicles,  put the car in gear. Be sure you have veered off the road and have your hazard lights on to let other drivers know you have stopped for repair.

 Step 2: Place a wheel chock or large rock behind the diagonal wheel, if facing uphill, or in front, if facing downhill, to keep the car from rolling.

Step 3: Get your spare, a lug nut wrench and the car jack. If necessary remove the hub cap and proceed to loosen the lug nuts before jacking up the car. Put one end of the lug nut wrench over a lug nut. For leverage, use a hollow pipe to slip over the end of the lug nut wrench. Loosen the nuts in a star pattern, loosening the first with a few turns and then moving to the nut located directly opposite. Work across the tire until all the nuts are slightly unscrewed.

Step 4: Cautiously jack up the car a littler higher than necessary to remove the old tire, making room to put the new tire on. Remove the lug nuts completely and set them somewhere you will not lose them.

Step 5: At this point the tire should be hanging from the threaded studs. Remove the flat and set it aside. Lift the new tire on the wheel studs, and remember that the valve where you add air always faces out. Replace the lug nuts, tightening them in the same way you loosened them in a star pattern around the wheel. You want to avoid tightening adjacent nuts one after the other.

 Step 6: Slowly lower the car jack, remove it and continue tightening the lug nuts as much as possible. Replace the hubcap, if removed, and you’ll be ready to hit the road.