If the glass back is cracked, carefully tape over the entire surface with packing tape.

Apply a heated iOpener to the bottom of the phone for about two minutes.

You may need to reheat and reapply the iOpener several times to get the phone warm enough. Follow the iOpener instructions to avoid overheating.

A hair dryer, heat gun, or hot plate may also be used, but be careful not to overheat the phone—the OLED display and internal battery are both susceptible to heat damage.