The first thing is to move your car as far as possible off the road so that you or the car are not hit by other cars on the road. If you are changing a tire at night, it would be a good idea to have a red flare a few yards behind your car. Before raising the tire up with a jack found in the trunk, you should block the back of the rear tire on the opposite side where you have the flat. You do this so the car will not accidentally move when you raise it with the jack. Before jacking up the car and taking off the hub cap, you should first loosen the lug nuts, and then completely remove them after the car is jacked up above the ground. You should place the jack on the bumper next to where you have the flat. After the lug nuts are removed, you can easily pull the tire and rim off of the studs of the car. Hopefully, you will have a good spare tire in your trunk to put on the car. Align the holes in the rim on the spare tire with the studs sticking out of the car, and push the tire onto the car. After doing this put the lug nuts on the studs and tighten them with your hand until they can not turn. After doing this, lower the car and then take a lug wrench to tighten all of the lug nuts. The final step is to put the hub cap back on the rim and then remove the block from in back of the opposite tire. Of course, you want to put the flat tire, block, jack, and lug wrench back into the trunk of your car. The process really isn't that difficult for anyone to do.