Acetone.
 

Will acetoning (think that's a word) ruin my tyres.

I have new tyres on uncompatable wheels, and would like to remove them.
Schumacher greens and yellows and Dboots.

Been told you can get away with it with yellows but not greens, unsure about the Dboots any advise would be appreciated.

My greens went rock hard, not tried boots tho...

The problem with straight out soaking them in acetone, or any solvent, is that it dries out/dissolves the oils in the rubber - and thus make any tyre harder than it was originally - and that's where guys have recently been trying a bit of a new technique of putting some acetone in sealable paint can, putting a tray or something in the can to keep the tyres from direct content with the solvent, and sealing the can and allowing the fumes to debond the CA over a few days.

Give it a try.
Worse that can happen is it doesn't work, and then you can resort to the old "bake 'em off in the oven" technique.

ah... my greens are in at the moment.

I have made a nice little setup though to do 16 wheels at once :D I'll take a pic soon.