Go ahead and warm up the back side with the tools you have. CPB Heating Pad, Heat Gun, or the iOpener work best.

Don’t forget that 90%+ Isopropyl alcohol is nonconductive. It helps make light work of the majority of steps in this repair.

If the adhesive is warm and has enough give you may start the opening porting with the iFixit Opening Pick(s). If not there is a different way to get the pick to penetrate the adhesive in the next step.