First of all, you need to have latest operating system on your computer. You can have OS X Lion on your Mac or Windows on your PC, but whichever operating system you have, you should keep it updated. Furthermore, you need to have iTunes 10.6.3 software installed on your computer. Besides, download and install iOS 5.1.1 and iOS 6 Beta 2. You can download iOS 6 Beta 2 from imzdl.com. But, make sure that you unzip the file if it is not unzipped before.
Then, plug your apple device with your computer by the help of USB. Sync your device with iTunes and back it up. Now, press and hold the shift key for Windows or option key for Mac and then click on ‘Restore’ button.
Go to the folder in which you have saved iOS 5.1.1. Open it and click ‘Okay’.
Wait until iTunes restores your device. Then, select ‘Set up a new device’. ITunes will ask to sync with the new device. Cancel the sync immediately.
Click on ‘Check for Download’ while pressing and holding the shift or option key. Now, go to the folder in which you save iOS 6 Beta 2. Click ‘Open’ and then ‘Okay’. Wait until your iTunes restores your device to iOS Beta 2.
Once your apple device has been restored, you have to configure it as per your requirements. Select ‘Backup’ in order to restore all your contacts, apps, media files and messages.
You have successfully installed iOS 6 Beta 2 in your apple device. Enjoy!