I have 2 phone numbers on my AT&T account. The one I don't want to change was eligible for upgrade and the one I want to use the new iPhone with was not. I ordered a 5S using the number that was eligible because an AT&T rep I talked to said I could use the phone with any number I wanted to. When the phone arrives, how do I change which number the phone is associated with? Will it ask during the setup? Can I move the sim from the iPhone 5 I am upgrading from to the new iPhone before it activates the included sim? I am concerned because the setup videos I have seen don't seem to give the opportunity to change the number. The reason this is an issue is that the phone currently using the number that was upgrade eligible is a few states away for the next couple of months. I would really appreciate any help or advice.