Remove the battery from the iPhone.

If your replacement battery came in a plastic sleeve, remove the sleeve before installation by pulling it away from the the ribbon cable.

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

Before you adhere the replacement battery, temporarily reconnect the battery connector to the logic board socket. This ensures that the battery is properly aligned in its recess.

Adhere the battery, disconnect it, and continue reassembling your device.

If your new battery doesn’t have adhesive preinstalled, refer to this guide to replace the adhesive strips.

Perform a hard reset after reassembly. This can prevent several issues and simplify troubleshooting.