Whatever way you choose to follow, don't overdo it. I could imagine boiling or chemicals making the wheel softer and/or make them brittle.
At least this could warp or weaken the wheel, at worst they'll snap when you are using the car, neither of which will end up being very productive...
Im not sure about the tyres and inserts either, foam inserts could fall apart, the moulded inserts may distort....
That said, ive never tried removing glued tyres from their wheels though, so the people that have already tried doing it and posted their experiences here are probably worth listening to more than me