Annealing Zinc Die Cast

Q. I have a zinc die cast object that has a rolled edge that holds a plate in place. It is a closed cylinder with the bottom sealed by a flat plate held in place by a rolled edge.

I'd like to lift the rolled edge up from the plate to remove the plate but want to do it non destructively.

I understand that zinc becomes more ductile over a very specific temperature range.
I'm hoping to be able to re-roll the edge back after lifting it.

My thoughts so far are to try and lift the rolled edge in a sort of spinning process, i.e., turning the object in a lathe chuck whilst lifting the edge with a pry. Any better suggestions to accomplish this would be appreciated, even if they are only SWAGs! :)

Thanks guys/gals,
Doug

(SWAGs are "Scientific Wild-a**ed guesses) :)