If any of the adhesive strips broke off and the battery remains stuck to the rear case, remove it by adding a few drops of isopropyl alcohol (90% or greater) underneath the battery near the stuck strip(s). After about a minute, gently lift the battery.

Don't try to forcefully lever the battery out. If needed, apply a few more drops of alcohol to further weaken the adhesive. Never deform or puncture the battery with your pry tool.

If you choose to use pry tools to lift the battery out of the iPhone, use extreme caution or you may damage the ribbon cables or the wireless charging coil directly underneath the battery.

If the battery remains stuck to the rear case, prepare an iOpener or use a hair dryer to heat the rear case directly behind the battery. This will help soften the adhesive.

Heat the iPhone until the rear case is slightly too hot to comfortably touch. Don't overheat the iPhone, or you may accidentally ignite the battery.

Alternatively, thread a strong piece of string (such as dental floss or a length of thin guitar string) underneath the battery.

Pull the string from side to side in a sawing motion all along the length of the battery to separate the adhesive. Do not deform or damage the battery.

To protect your fingers, wear gloves or wrap the string ends around a tool (such as the two screwdriver handles shown in the image).