Lay the iOpener over the plastic tab to loosen the adhesive. Let the bag sit on the device for approximately 90 seconds before attempting to open the panel.
Use a metal spudger to carefully pry near the Lightning connector and under all parts of the front panel assembly: the front glass/digitizer, the LCD display and the metal midframe.
The adhesive under the metal midframe/display assembly is quite strong and the components are fragile, so go slowly and gently. Make sure you do not bend the LCD screen.