Learn how to install and remove the battery, SIM card, and memory card (microSD).
MicroSD/memory cards expand the storage capacity of device and are sold separately. This device can use a microSD card up to 1Tb.
In this tutorial, you will learn how to:
A No SIM notification will be displayed in the Notification bar of the lock screen when there is no SIM card in the device.
Remove the back cover by inserting your thumbnail into the notch on the top right of the device and pulling up. 
Remove the battery by gently pulling up from the notch on the bottom.

Place the battery in the battery slot with the gold contacts on the battery lined up with the gold contacts on the phone.
Place the cover on the back of the phone and gently push in until the cover clicks. The cover should be flush with the rest of the device.