What about using a low-temp oven instead of a heat gun (or is using a heat gun easy enough)?
What would be too hot? Would 70˚ C be too hot (60˚, 50˚)?
I also see that it says "forget to stick the camera bracket down to the NEW FRONT DISPLAY GLASS before reassembly." Do people that do this repair ever reuse the old glass that they just removed with the heat-gun with success?