If you want to cut the laminate, use a new, SHARP blade in a Utility Knife. IF you want to remove the 'over-lapped' formica that's behind the cabinet, loosen (not remove) the cabinet from the walls a little. Then, with whatever tool you can use, like maybe a Spackle Knife, 'slit' the backing BEHIND the laminate, and remove it. Since the cabinets and new tile will cover the wall, you don't have to be EXACT in how the laminate is removed. After it's removed, screw the cabinets back into the wall. Of course, EMPTY the cabinets first, and consider (possibly rigging something if necessary with 2x4s, or something) temporarily holding up the cabinets while you loosen them from the wall.