Hello, sorry if this is a repeated post. I have been away for a while and wanted to be sure on this. I want to update my jailbreaken/unlocked 3GS 3.1.2 to ios 4.0. What is the best way to do it ? I do have Cydia show that "it has SHSHs on file for 3.1.2,3.1.3,4.0,4.0.1,4.0.2". Thank you very much !