When inserting or removing the SIM card, power off the device before opening the SIM tray.
Use the SIM eject tool or a paper clip to remove the SIM tray. Note: Press in firmly to eject the SIM tray.
Remove or place the SIM card into the SIM tray. Note: A SIM card is required in order to use cellular services when connecting to the AT&T network.
Push the SIM tray back in until it clicks into place and is flush with the side of the device.
Turn iPad back on, press and hold the Sleep/Wake button until the Apple logo appears.