To remove the battery, simply use the provided tab labeled "pull" to separate the battery from the casing. Do not pull the battery all the way out quite yet; there is still the matter of detaching the battery connector.

There is a small application of adhesive on the underside of the battery. When lifting the battery away, if you feel a bit of resistance, feel free to press down on the casing to give yourself a bit of leverage.

Caution: Be very careful not to puncture the battery in this step or while recycling; doing so can result in the release of dangerous gases and an explosive reaction.

Finally, using a spudger, separate the end of the battery connector cable, (held in place by another small application of adhesive and a plastic pin) from the casing.