Once the battery is loosend from the adhesive on the motherboard you can now flip the motherboard over to release the battery connection from the motherboard.

Make sure to hold the battery in place while doing this so you don't damage anything on the motherboard.

Free the battery connection with a plastic pry tool.

Now we can remove the battery from the motherboard.

The battery's ribbon cable can be a little tricky to get through the whole in the motherboard.

Now the replacement battery can be installed and you can follow these directions in reverse order to reassemble the phone.