As lawnmower man said, find the 3.1.2 software and put it in a folder you know, click the restore button on itunes but hold shift at the same time, it will ask you to find your corresponding software or something? It will take abit, but don't unplug it! Blackra1n and redsnow are both preety good, make sure you get it all from decent websites though, red snow comes with its own sort of guide but takes abit...