Another update, I peeled the film off the aluminium bed, it has to be done with a hot bed or else it just tears.
The I found is that the glue was left on the metal and removing it wasn't easy, I had go at it with a scotch brite sponge, acetone seemed to soften it somewhat but not enough.

I think I'll rather do tests on how to best apply the film on small sheets of aluminium rather than a full print bed.