I had '76 Ford pickup with the crispy, rock-hard window tint glue. I used a single edged razor blade and it took quite a while, but I got it off. Ammonia cleaned up the residue.
I'm sure it's possible, but I can't fathom an adhesive on glass that won't relent to a new, sharp single-edged razor blade, held at a narrow angle of incidence to the glass. Maybe a fairly aggressive scotchbrite pad would work, but you'd be risking scratching the glass with most of them. Maybe call a window-tint shop and ask what they use in worst-case scenarios?
Goof Off contains xylene, acetone, alcohols, and a mixture of various other solvents. This is why it works so well, but also why it eats into nearly any plastic on which it is spilled.
Colo Springs, CO
'78 FJ40, '89 FJ62, '98 4Runner