During reassembly (once you have put the display cable back into its socket), I recommend plugging the charger cable into the phone for a few seconds to see if you see the lightening bolt (charging indicator) on the front panel. This will allow you to be certain that, both, the battery and display connectors have been properly and securely connected.
This step was a challenge. The picks are quite thick. I ended up using a box cutter knife to carefully separate one corner. Then I used one of the picks to complete this procedure. Once I realized that this worked, I breathed a sigh of relief. Then I did the same thing for steps 5 & 6.
I heated the iOpener several times to no avail. Then when i switched from the pick to a box cutter (see my comment on next step) it turned out that the glue WAS heated enough.