Do not do it yourself. It's cheap junk and will turn purple and bubble on you.
I had my last car tinted by a very good tint guy in 2010 and sold the car march of this year. The tint was still prefect! 7 years! It was Llumar, very good tint. But makes a difference
I'd rather have the tint installed by a professional rather mess things up.
I tried doing the tint job by myself, yet in my case I spoiled the tint from the very first window and threw the kit away...
After that I made a decision, that I will not be doing that again, too frustrating, you know.