I think I'm going to sell my factory sealed iPhone 5 that I'm going to purchase today. I was eligible for an upgrade and trying to make a few bucks. Can someone help me on the process... 1. I sell the phone on ebay 2 Someone buys it and then I ship it to them... 3. What's next? Can't they start using the SIM card associated with that line? 4. Whose line does it actually get activated under? Before I leave the store should I have them set up a new IMEI number with the phone I want to use?