I am going to try and buy an iPhone on launch day at an AT&T retail store. I don't have a pre-order or any type of reservation. My mom's line is eligible for an upgrade, mine is not. I will be using her upgrade for my line. She will be keeping her non-iPhone phone that she currently has. My mom lives in Southern California while I am in Northern California. I am an authorized user. Does she or her phone have to be present with me for the upgrade swap to take place? Will they be making some new SIM card for her phone or can I take care of everything without her or her phone needing to be there? THANK YOU.