This is one of those basic life skills that you need to know. Even if you don’t drive, this knowledge might just come in handy and keep you going when you’re far from home.
Find a safe place to stop the car, preferably far away from traffic. Make sure you stop on hard, level ground. If the ground is soft, the jack could sink into the ground, and if it isn’t level, it could fall off the jack. Shift your car into park or in reverse if it has a manual transmission and set the parking brake.
Open the trunk or cargo area, and remove the spare tire, jack, and lug wrench. Use the wrench to loosen the lug nuts that secure the wheel. Don’t remove them; just loosen them slightly. Next, find the reinforced jacking points. They’re underneath the car just behind the front wheel or in front of the rear wheels. Check the owner’s manual if you have doubts.
If possible, put something under the tires on the opposite side of the car so that it won’t roll when you jack it up. A stone, brick, or a block of wood will do. Put the hack in position under the point closest to the flat and lift the car until the tire is just off the ground.
Now remove the lug nuts completely and put them in a safe place nearby, so you don’t accidentally kick and lose them. Pull the flat off and slide the spare onto the threaded nuts. Make sure the spare’s valve, from where it’s inflated, is facing towards you. Screw the lug nuts on and tighten them by hand. Then use the lug wrench to tighten them some more but not all the way. Then lower the car carefully and remove the jack.
After the car is resting fully on all tires, remove the jack. Now use the wrench to tighten the lug nuts fully. Lean into it with your body weight. They need to be as tight as possible. Next, stow the flat tire, jack, and wrench safely in the trunk and secure them, and you can drive off.