APPLICATION USING WET TRANSFER METHOD

If you use Rainex on the surface you will be applying the decal to, try using Formula 409 to remove it. Use window cleaner or alcohol to clean glass surfaces. The surface must be clean and free from oils, waxes and dirt in order for the decal to adhere properly.
Mix a solution of water, and dish soap (a few drops to a gallon of water). Use a spray bottle and wet the area where decal will be applied.
Remove the decal's backing and place the decal, still attached to the transfer tape, to the wetted area. The decal's backing is the heavier gauge paper. The decal may now be moved and repositioned correctly.
When the decal is in its final location use a small squeegee to squeeze the water and detergent solution out from under the decal. Allow 1-5 minutes drying time. Allow plenty of drying time because if solution remains under the decal, it will not adhere well enough to remove the transfer tape.
If there are any air bubbles under the decal that cannot be worked out to the edge, use a small pin to puncture the bubble and remove the air.
Remove transfer tape carefully by pulling at a 180° angle. If letters begin to pull up with the transfer tape, use your squeegee to go over the lettering again. Then attempt again to remove the transfer tape.

APPLICATION USING DRY TRANSFER METHOD

Take a credit card and flatten both sides by rubbing over the decal. Make sure all air bubbles are out.
Look to see if decals are cut for the inside or outside.
Turn decal upside down and pull decal's backing off SLOWLY. The decal's backing is the heavier gauge paper. Using a pin (or similar pointed object), hold the edges of the letters and all small areas while pulling away backing. If a letter moves, just position it back in place by pushing backing down and moving letter to its original position.
Position the decal and flatten it from the center out. Use a credit card again to flatten as much as possible. The transfer tape will allow you to rub the decal without damaging it.
Peel back the edge of the transfer tape slowly, taking special care with small letters and corners to insure they are stuck to the glass and not to the tape.
Take your fingers and check all edges and make sure they are tight. If you have an air bubble, use a pin to poke a small hole, allowing air to escape. The bubbles may disappear after a day or two.
Once the decal touches the glass or paint, in cannot be moved again!