If you don't have any high concentration (over 90%) isopropyl alcohol at hand you can prepare an iOpener and apply it to the rear glass for at least three minutes to loosen the stretch-release adhesive underneath the battery.

Insert a plastic card underneath the bottom edge of the battery.

Slide the plastic card along the edge of the battery to separate it from the rear case and to cut the adhesive.

Use your plastic card to carefully pry up the battery.