How to balance tires
Things You'll Need
Remove any previous wheel weights which may be present on the wheel. They complicate the issue and make it harder to balance the tire. You can do it, but it entails a bit of a hassle.
Place the tire and wheel on the balancer by inserting the shaft through the wheel hub and securing it in place. Make sure the wheel is as centered as possible on the balancer, though it doesn't need to be exact.
Spin the wheel gently in the balancer. You will notice the heaviest part of the wheel being drawn to the bottom and the lightest part to the top. Allow it to settle in that position, then mark the lightest part on the tire with a piece of chalk. Repeat the process to make sure you've marked the correct spot.
Attach the wheel weights, adhesive side first to the part of the wheel
just below the spot on the tire you just marked. This should counter the imbalance in the tire.
Move the wheel so that the weighted part is in the 3 o'clock position. Release the wheel. If it rolls clockwise so that the weighted position is on the bottom, you've added too much weight. If it rolls back up to the top, then you haven't added enough.
Continue adding or subtracting wheel weights from the marked location until you have attained the right balance. The weights should remain in the 3 o'clock position naturally, without spinning either up or down.
Secure the wheel weights to the wheel a little further by using duct tape or similar adhesives. The adherent used in wheel weights is not usually very strong and can use some help in staying where it is supposed to.
Remount the wheel to the car, taking care that the lug nuts are secure.Source: ehow.com