Use suction cups to pull back on broken screen.

If your screen is heavily cracked, cover it in tape. This allows the suction cup to grip better and will prevent glass shards from falling off.

The screen is held in by tape. Be gentle and patient, it can be detached. If needed, you can reinstall the back cover for more leverage.

During reassembly, test the new screen before applying adhesive by reconnecting the display cables and powering on your phone. Power your phone off before continuing reassembly.