Upgrade iPhone to 3.1.2 via iTnunes if not already updated.
If you do not have the firmware can be downloaded from here:
Blackra1n for Windows download directly from the official site by clicking here and then the Apple logo.
Connect the device to your computer via USB (to be turned on) and close iTunes.
2. Click that button, and you’ll notice the words “Entering Recovery”. In those seconds, the program will launch a completely automated process that will put the iPhone / iPod in recovery mode and then run the Jailbreak and install the application on the device Blackra1n.
3. IPhone GeoHot image will appear full screen on Mac and meanwhile you will notice this in writing:
4. The Jailbreak has been completed and was successful. Wait those 20 seconds it took to restart the phone and when you are on the SpringBoard will not have to do is launch Blackra1n through the appropriate icon, and download Cydia.
End! You can enjoy your device updated, unlocked and jailbroken with the latest available firmware and Cydia. The whole process, even counting the time for a restart of the device, takes about 30 seconds!
Restore backup or set up as new iPhone?
We do not recommend backup restore through iTunes if these were made by a firmware 3.0.x. A substantial firmware update results in significant changes that often a backup can change, compromising the proper functioning of the device. It ‘always advisable to configure your phone as a new device .. up to run a manual backup (via SSH) only for SMS. For the address book, mail, bookmarks, applications, music and photos, to do a new sync with iTunes. For applications Cydia, reinstall only those necessary.