to remove tint on a window without a defroster,
roll the window down a little and peel the tint away from a corner a little
pull the tint straight down the window, not towards the interior
use a spray bottle with water and a good squirt of any soap,
spray the adhesive on the window where you just pulled the film away,
using a single edge razor blade, more than one will be used, to scrape the adhesive still on the window holding the razor as close to parallel with the window as possible.
work your way down pulling the film as you go
keeping the adhesive wet makes it easier to get off
IF the tint does not come off in one piece, it sucks to be you
A warm day is much better than a cold day for this process
Hope this is helpful