I contacted Gazelle to sell my iPhone 4. When they send me the box to ship out my iPhone do I just have to take out the sim card and place it in its original box for shipment to Gazelle? Sorry if this is a dumb question because on their website it states that I have to deactivate my line prior to shipping, but if I do that then I lose my grandfathered data plan. Any help on this would be very much appreciated.