1) putting ice, on the tiles to "freeze" the tile, thus making it and the underlaying adhesive brittle and easier to pop off.
I've never done that, nor have I ever seen it done.
I have seen 2) using a propane torch with a flare fitting to heat the tile and adhesive, which makes it more pliable and somewhat easy to remove using a putty knife of similar tool. It does stink. You may want to ensure good ventilation while you're working, and may even want to wear a HEPA-type maks that works with organics. Wear gloves, as the pliable tile can be very hot.