With the AT&T Velocity USB Stick attached to your device, open http://attusbmodem or http://192.168.1.1 in an internet browser.
ENABLE THE PIN: Select the Off circle to turn off Domestic Data, then select Apply.
Select Settings.
Select the Advanced tab.
Select the Enable SIM PIN circle.
Enter the Current PIN, and select Apply. Select OK to confirm.
CHANGE PIN: Select Change PIN.
Enter the Current PIN, then the desired New PIN. Enter the desired New PIN again to confirm, then select Apply. Select OK to confirm. Note: In order to change the SIM PIN, you must enable it first. The nano-SIM will be locked if you enter the wrong PIN three times consecutively.
DISABLE PIN: Select the Disable PIN circle.
Enter the Current PIN, then select Apply. Select OK to confirm.