My Grandfather purchase about 40 Iphones 3GS,4G and 4S, with ATT. We are wanting to resale this to help with our Cheer expense to go to the Orange Bowl .
Many students want them to be used with StraightTalk.
What is the best way for us to allow StraightTalk to be used? Or is there a service which isn't too expensive which can do that for us.