If you are experiencing trouble with your battery and need to replace it, follow this the guide.
Locate the power button at the top of the phone. Depress power button for 2 seconds until a menu appears.
Once the menu appears, select the "power off" option. Wait until the phone is completely off.
Place thumb on the back cover, and push down towards the bottom of the device. Once the cover releases, pull it away from the phone and set it aside.
Find the yellow pull tab located in the upper left corner. Pull the tab until the battery dislodges. Grab the battery by the raised edge, and remove it from the case.
The battery has been successfully removed.