Remove the battery.

Do not reinstall a damaged or deformed battery, as doing so is a potential safety hazard.

If there's any alcohol solution remaining in the phone, carefully wipe it off before installing your new battery.

If your new battery didn't come with adhesive preinstalled, refer to this guide for help replacing the adhesive strips.

Perform a force restart after reassembly. This can prevent several issues and simplify troubleshooting.