"Normal vinyl removal techniques are not generally appropriate when removing frosted vinyl from glass. Applying heat can cause the glass to crack or shatter. Using a solution of water and dish soap, saturate the vinyl with a fine mist, then cover with bubble wrap or plastic for two hours to prevent drying. The mixture of soap and water will penetrate through the vinyl and make removal much easier, without using heat."
"Whether you use a torch or a heat gun on your wraps, heat is an important part of any wrap. Heat can be used to make pressure sensitive vinyl conformable around curves, rivets, and other irregular surfaces. Post heat is also a critical step when doing vehicle wraps to help "set" the vinyl. Direct heat should especially be applied to areas where the vinyl has been stretched. Slowly move the heat source across these areas until the Mastercool Infrared Temperature Gun reads no more than 200 degrees Fahrenheit (most manufacturers recommend not heating vinyl beyond 200 degrees), then move the heat source approximately one inch every two to three seconds. This technique relaxes the stress on the vinyl caused by stretching, which will help prevent lifting and tenting. Finally, heat is often used to remove a wrap, especially in cold environments. Heat allows the vinyl to come off faster and improves the ability to remove the adhesive with the vinyl instead of leaving adhesive on the surface which would require even more labor to remove."
WARNING: Do not use heat sources near gas tanks or flammable substance