1When you get a flat, pull over immediately and turn your flashers on. This will help other drivers see you. Your spare should be located in your trunk. Make sure to check the pressure in your spare (it needs to be full and tight). If it’s too flat, you shouldn’t and won’t be able to use it. At this point my best recommendation would be to call a towing company or, if you are a member of AAA, you should definitely call them. If it is tight, go ahead and set it to the side.
Nex thing to do is to find the jack and lug wrench. Those are usually located under the spare tire =) Make sure at this point you pull out your auto manual which should be located in your glove compartment….. Honestly, I’m not quite sure where mine is, but hopefully you guys know where yours is LOL This manual will be full of helpful information regarding if your car/truck/whatever 
has wheel locks, etc.
NOW, for the fun part =) Using the flat end of the lug wrench, pry off the hubcap (of the flat tire…of course 
Also, having a screwdriver right about now would be helpful. Next, you’ll need to loosen the nuts. You do this by turning the lug wrench counterclockwise about one turn. I’ve been known to have to stand and jump up and down on it if it’s too tight (use the ball of your feet)…. just be careful if you do that. And make sure your not trying that kind of stuff near traffic… Now, place the jack behind the wheel if it is a front wheel or in front of the wheel if it is a back tire. Trust me, it’s not impossible to lift the vehicle even if you’re little. I’m only 5 ft and weigh about a 100 lbs, and I can do it =) Soooo just keep saying “I can do it =)” Basically, the jack is the leverage, so there is really nothing to worry about when it comes to your size. All you have to do it pump it. Place the lug wrench in a groove on the jack. You’ll see it =) Promise. Then just pump the vehicle up. Approximately 3-4 inches is recommended. Now you need to loosen the lug nuts and take the wheel off. Squat and use your upper thighs, do NOt, I repeat, DO NOT use your back. Once you get the tire off, roll the tire off and place it aside. Now you can slide the spare tire onto the axle hub, and screw the lug nuts on tightly. YOU’RE ALMOST DONE!!!! Lower the jack, again, you can use your feet for this. Place your tire, and all your tools in the trunk and Drive to the closest body shop. If there isn’t one around, you can also go to a gas station. YAY!!!! YOU DID IT! =)