When the SIM card is missing, the Missing SIM icon will display in the Notification bar.
REMOVE BACK COVER & BATTERY: Remove the back cover by inserting your thumbnail into the notch on the bottom left of the back of the device and lifting up. Remove the battery by gently pulling up from the notch on the bottom.
INSERT/REMOVE SIM CARD: Insert the Nano-SIM card into the SIM slot with the metal contacts facing down and the notched edge going in first. Push until it is all the way in. To remove, simply slide it out.
INSERT/REMOVE MEMORY CARD: Insert an optional micro SD/memory card up to 32GB into the microSD card slot, with the metal contacts facing down and the notched edge going in first. Push until it is all the way in. To remove, simply slide it out. Note: SD cards are sold separately. To prevent data corruption, it is recommended to unmount your memory card before removing it. To unmount your memory card, swipe down from the Notification bar with two fingers then select the Settings icon > General tab > scroll to and select Storage > Eject icon.
REPLACE BATTERY: Place the battery in the battery slot with the gold contacts on the battery lined up with the gold contacts on the phone.
REPLACE BACK COVER: 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.