The battery is still connected to the headset by a cable connector at the top of the battery recess. Do not try to completely remove the battery before disconnecting it.

While removing the battery, keep it as close to the recess as possible to prevent straining the cables.

Use your finger to lift up the right side of the battery about 0.5 cm (when the battery cables are oriented up).

You only need to lift it high enough to be able to pull it out of the recess.