Apply a suction cup to the screen, as close to the center of the bottom edge as possible.

Pull up on the suction cup with strong, steady force to create a gap between the screen and the frame.

Insert an opening pick into the gap.

Depending on the age of your phone, this may be difficult. If you're having trouble, apply more heat to the edge and try again.

If your screen is badly cracked, cover it with a layer of clear packing tape to help the suction cup adhere. Alternatively, you can pull using very strong tape instead of a suction cup. If all else fails, try supergluing the suction cup to the broken screen.