To get the wheel off, you'll need to raise that corner of the car.

• Most often, the spare will be held in place by a bracket or a bolt that unscrews by hand pretty easily.
• Raise the jack enough so that it just touches the car. Almost all jacks are raised by inserting the jack handle into a socket on the jack body, and turning the handle. Some jacks are raised with a scissor-type motion. In a scissors-type jack, the socket can be hidden in the center of the jack body, while in others it may be more obvious.

Don't worry about holding the jack in place while turning the handle. You can position the jack when it's raised enough to reach the car.

• Once the jack is raised enough to touch the car, it's time to position it properly. Each manufacturer has a special place designated for the jack contact--that's the spot where the jack lifts the car. If you have a manual, it should contain this information.
  
  The positions for the jack are usually about 6 to 12 inches behind the front tire, or 6 to 12 inches in front of the rear tire. Search a few inches in from the car's body for the car's sturdy frame, and avoid using the suspension.
  
  Make sure that the jack is flat on the ground. Crank it a few more times to secure it properly.
  
  
• When you're certain the jack is positioned properly, continue turning the handle so that the car rises off the flat tire. You'll need to fit a fully inflated tire under there, so give it a few extra turns to make sure there's enough room.