I believe that a heated floor shouldn't have elements everywhere through it. They should pass back and forth or if its heater be water pipes then its laid back and forth across the floor in a grove cut in the sub-floor. I would try it myself after trying to find out a little info on the exact type of heating is in the floor. Then to do it, you have to cut the grout line all around the tile, then take a hammer and start breaking the tile from one corner to the other. Depending on the heating type in the floor, you might take a screwdriver to help get the tile prayed up. Since its cracked it shouldn't be too hard.