I am using a family member's upgrade to get 4s shipped to my house. She has a 3Gs and I have a 4. She wants to keep 3Gs and I'll be giving the 4 to my brother (has a 3G or 3Gs, not 100% sure). Here is my question: Can this be done without involving AT&T? I bought a sim cutter and some sim adapters. Can I just take my iP4 micro sim and put it in new 4s, put the new 4s micro sim in an adapter back into eligible lines 3Gs and cut my brothers sim and put into my 4 and be done with it? Is it really necessary to have IMEI #'s switched? I would just rather not have to deal with AT&T on release day. Sorry if this is confusing.