By now you must be well aware that the iPhone 5 sold like hotcakes yesterday. At this moment, Apple has pushed shipping dates for new orders back by another 2 week, so Apple fans are in for a long wait.
Nevermind iPhone 5, get iOS 6 now (instructions)
However the same isn’t neccessary for iOS 6. If you have an device compatible with iOS 6 (iPhone 4S, iPad, etc) you can get your hands on a leaked version now if you want it.
Lifehacker did test the leaked files and they came across no issues, however they cannot guarantee that no problems will arise. The leaked iOS 6 files are said to work on the iPhone, iPad and iPod Touch, but again there is no guarantee and as always there are risks involved when upgrading.
One of the first things you need to do if you want to upgrade is to make a backup of your iOS device using iTunes.
Once you have downloaded the files for iOS 6 you can then install it on your handset (you can download the appropriate file for your device from here). Next:
Open the disk image .dmg and look for the iPhone software update file with the extension .ipsw for your handset and drag it onto the desktop. If you use Windows you will also need 7-zip to do this and you will also have to open up the .hfs which is inside the .dmg.
Open iTunes and then connect your device to the computer.
You device should show up automatically but if not select it and then head into the summary tab.
If you are using OS X then hold down the option key or on Windows the shift key and then click the Restore button. Browse to the .ipsw file which you downloaded, choose it and then just sit back and wait for the update to complete.
If needed, restore the back-up you made of your device and then sync with iTunes. If you follow these steps you should now have iOS 6 on your device.