If your iPhone has a cracked screen, keep further breakage contained and prevent bodily harm during your repair by taping over the glass.

Lay overlapping strips of packing tape over the iPhone's display until the whole face is covered.

This will keep glass shards contained and provide structural integrity when prying and lifting the display.

Wear safety glasses to protect your eyes from any glass shaken free during the repair.

If the broken glass makes it difficult to get a suction cup to stick in the next few steps, try folding a strong piece of tape (such as duct tape) into a handle and lifting the display with that instead.