Aporte original por: Denis ,
download lastest ispw iOS 5.1.1 download lastest sn0wbreeze and run it create a custom ispw and install cydia in it than restore via itunes in DFU mode follow sn0wbreeze instructions. After restore go to cydia and search for ultrasn0w and install it restart the iphone and will be unlocked to the lastest iOS. You can search any tutorial on youtube or google. Good luck.