Apple has released iOS 6 for all compatible devices, this includes the iPhone 5, iPhone 3GS, iPhone 4, iPhone 4S, iPad 2, iPad 3, iPod touch 4th gen, and iPod touch 5th gen. iOS 6 includes a variety of new features and refinements, makes Sharing possible with Photo Streams, adds Apple’s new Maps app and turn-by-turn directions, and brings Siri to devices like the iPad 3. Upgrading is simple, back up first and then use one of the following three methods to install the update.
Updating to iOS 6
Wait! Back Up First: Before beginning any iOS update, it’s a good idea to back up your device. The easiest way is with iCloud, which can be done through Settings > iCloud > Storage & Backup > Back Up Now, but you can also backup through iTunes.
OTA Update: The best approach for most users is to update to iOS 6 using Over-the-Air, this can be done by opening Settings, tapping General, then tapping “Software Update” and then installing. This is generally the fastest method and it only downloads a delta update, meaning the changes between your current iOS version and iOS 6.
Updating through iTunes: iOS 6 can also be installed directly through iTunes. Be sure to have the latest version of Tunes 10.7 (or later) installed before doing so. Connecting the device to the computer and opening iTunes is generally sufficient.
Updating through IPSW: Considered more advanced, you will need to directly download iOS 6 firmware files from here and use them manually.