The battery is securely adhesed to the housing; use a hairdryer or hot air gun at moderate heat for 10 seconds to loosen the adhesive.

Use a plastic guitar pick or spudger to separate the adhesive from the plastic housing. There should be less resistance; if it's still not budging, re-warm the area and try again.

Do NOT use a sharp, metal object; this will risk puncturing the battery and causing a fire!

This adhesive is very tough, lasting several years. Be patient cutting through.

Once the adhesive is freed, separate the controller apart more to handle the battery, and remove it from the main handle.

The battery is plugged into the printed circuit board via an MX2 connector.

Be careful when removing! The inside chamber holding the battery has several sharp corners that could puncture the battery, and cause a fire!