Once the screen is warm to the touch, apply a suction cup near the top edge of the phone right under the earpiece speaker.

If the phone's screen is cracked, the suction cup may not stick. Try lifting it with strong tape, or superglue the suction cup in place and allow it to cure so you can proceed.

Pull up on the suction cup and insert the tip of an opening pick under the display near the earpiece speaker.

Slide the opening pick to the top left corner of the phone to cut the adhesive.