I have a 3GS with 3.1.2 that has SHSH. It was JB/UL before. I restored it and just used Prepaid sim to activate and get passed the Itunes screen. Can someone please help me with JB and UL this phone. I have done it before but it was a long time ago and I simply followed instructions. I do not know how to use SHSH files do not want to ruin my iphone. Thank you very much for your help.