I have an iPhone that's come from 1.0.2 every step of the way, and it's activated (originally using iNdependence). I do not have an iPhone plan. What will I need to do in iTunes to upgrade to 1.1.3? It is jailbroken. It is NOT unlocked. I have my old AT&T SIM in it on my old plan - what will I need to do to ensure 1.1.3 works properly?