I ordered another iphone 5 16gb. She currently has my 64gb White iphone 5 which I am taking back. Now I ordered it under my account. How do I go about activating it for her on her line? I know the sims can be swapped. AT&T btw. Can I just take her SIM put it in that phone and it works, put the new sim in the older iphone 5 64gb, and activate it there? What is your experience with this? It's coming tomorrow so I wanted to prepare.