I have 2 mobiles on my AT&T mobility account. Both are iPhone 3GS phones. One got stolen over a week ago and I have suspended that mobile on my account. I just upgraded my other 3GS line to a 4S and want to use that 3GS phone on the other mobile that is currently suspended. I am assuming the new 4S comes with a new SIM card that will be activated once I activate the 4S, meaning the SIM card in the 3GS being replaced will be de-activated. What are the next steps to use my 3GS phone on my other mobile number where the phone was stolen and is currently suspended?