I want to buy a 6 outright, for AT&T. I have a 5s, and I have a plan, but I just want to buy my phone and not worry about the contract or upgrade, etc etc. There are 6's available at Best Buy (which is funny since the Apple Stores around here in Palo Alto are sold out). If i just walk in, buy it, what is the process for switching? Can I just open it, swap the sim cards, and do a restore from my iCloud backup of my 5s? Or would I have to do some tomfoolery with the sim-card that comes with the 6 with AT&T regardless of the non-upgrade status. I've always done an upgrade, but this time I just want to buy the phone. Ideas?