First, you need to locate the tools you’ll need. Look in your auto’s manual to find where the jack, lug wrench and spare tire are located. A word of caution before you start: Make sure you are well out of traffic on a flat, level area. You can drive, really slowly, on a flat for a little while until you find a safe area.
While your car is still on the ground, use your lug wrench to loosen the lug nuts (usually 4-5 or 6) that hold the tire on. Turn them to the left, counter-clockwise. Remember, “lefty-loosey – righty-tightly.” Loosen them until they turn easily, but do not remove them yet. If you try to loosen them when the wheel is up off the ground, the tire spins and that makes it hard to loosen them.
Make sure your manual, the emergency brake is engaged. Brace your other tires with a rock or piece of wood as an added precaution so the car doesn’t roll. Position the jack under the stress point on the frame of the car nearest the tire you want to change. If you look and feel with you hand along the very bottom edge of your vehicle, you’ll find an indent or a turn in the metal. Expand the jack either by cranking the handle or by ratcheting the gear and do this until it is snug between the car and the ground.
Start lifting the car by continuing to expand the jack. Go slowly and check that the car isn’t going to shift as you raise it. Keep raising the car until you have enough clearance to accommodate the size of the spare tire.
Now you can remove the already loosened lug nuts, keeping those little buggers safe and together. Take off the flat tire, and replace it with the spare tire. Thread the lug nuts back onto the bolts the were on. They don’t have to be on the same bolts, but one thing you must do correctly is to make sure they go back on with their beveled edges facing in, towards the car. This keeps the wheel firmly on the hub. Using your lug wrench, tighten them until they are snug, but don’t try to tighten them too hard.
Gently lower the car by reversing the jack’s action until all four tires are on the ground. Now tighten the lug nuts as hard as you can! Hard! Until you hear them squeak! All of them. Gather up your old flat tire, all your tools, and put them back in your car. Remember to remove anything you used to brace the other tires.
Get thee to a service station! Now! Today! First thing! You’re now driving without a spare tire, and if it happens again, you’re up a creek without a paddle! Get your flat fixed (or get a new tire) and have it put back on. Have them check to make sure your spare is in good condition too–for the next time.