How do I remove a stuck resin print
There are generally 3 ways, in order of least to most desirable, and at times you need to combine them in an escalation:

Toss the vat. This is the most expensive and generally should only be the last resort, for example, if you damage your film.
Careful Brute Force. This can damage the film, but carefully getting a wedge between the film and the print might be the only option to remove the last bits sticking to the film. If you have to resort to this, take your time.
Using thermal expansion. We all know that materials expand when you heat them. The reverse is also true: materials shrink if you cool them. Different materials shrink differently. So by cooling the vat with as little liquid resin and the print inside can lead to the print 'popping' free, just like in an FDM printer. Note however that this might not work on its own in case you made a suction cup (then you need to resort to brute force or drill a hole into the top), and you should take extreme caution not to contaminate any food with resin, as the stuff is not safe for consumption at all. With the right setup, you might be able to heat the build plate carefully while the print itself is kept cool.