You can, although seeing how big the glass is, you might break it. Specially if it is not all hot (hot, not warm) which is a pain for such a big glass and such a big aluminum frame that will be dissipating the heat.
My method is to tear through the adhesive using a plastic tool such as a guitar pick, horizontally and parallel to the frame and glass.
EDIT: if you are going to use the iOpener, heat one side, cut through; heat the next side, cut through while still hot, until you have done all 4 sides.
Must use that plastic tool ONLY as described above, as a cutting tool (be careful around the FaceTime camera), and NEVER to lift the glass even slightly. This will cause it to break.
Once the adhesive seal is broken all around, you can manually lift the frame, ideally by using suction cup.