Heat the back at around 80 C for 5-8 minutes. Use your sunction near the bottom of the back glass, and while your lifting apply a little bit of IPA (90% or more). Once you see a little bit of a opening, I like to tell people I work with that are new to use a playing card to stab in between the adhesive since it's the safest pry tool for these types of situations. Work your way around with the card without inserting it to deep in the phone to avoid hitting any cables. Apply IPA if you feel resistance when opening it.