Let's get started!
Step 1: Gather Your Supplies
1 - Razor Blade ($1 for a 5 pack)
1 - Upholstery Steamer ($29 at the store at most)
1 - Set of Gloves (you should already own these)
Pretty short list. Make sure the gloves are heat resistant. I'm using Nomex Aviator Flight Gloves with a leather lining. The Nomex won't melt from the heat and the leather protects my hands from direct contact. Also, it's better to get a steamer with a hose and head, it's easier to work with.
Why steam? The glue from window tint comes off MUCH easier with heat. You can use a heat gun or a hairdryer, but to transfer heat the fastest into the glue I used steam. When the water molecule in the form of steam lands on something, it changes from a gas to a liquid. When it does this, it transfers all of that extra energy to keep it in gas form into the object it lands on. Using steam like this, you can transfer heat into stuff that you can't (or don't want to) light on fire but need to make really hot. This is also why steam will burn you really bad and you need to wear gloves while doing this.