To use your username instead of carrier, on your lock screen you must 1st. go into settings then go into Security ,then screen lock then from there choose and select , Swipe , pattern , pin , or password. Next select owner information> type in your name of choice. REMEMBER to be sure that you check the box below that says show owner info on lock screen .. This MUST be selected in order for your desired name to appear on the lock screen...... hope this was useful info..