Thanks to iH8Snow for making it possible to downgrade iOS 5.0.1 to iOS 5.0 Custom Firmware using iFaith. Apple has tried to keep the iOS 5 users stick to it by regularly upgrading it. It was also next to impossible for those users to downgrade iOS 5 using SHSH blobs saved by TinyUmbrella or even Cydia.
However, now it’s possible to downgrade iOS 5.0.1 to iOS 5.0 using iFaith, that is the iH8sn0w’s iFaith app on your iPhone, iPad, or iPod touch.Learn from the following tutorial how to downgrade iOS 5.0.1 to iOS 5.0:
[Important: You must have APTicket + SHSH blobs file saved using iFaith for the firmware you are downgrading to.]
Choose the b ‘Build *signed* IPSW w/Blobs’, as shown in the given screenshot.
Now get the Blobs file saved with iFaith, while browsing for the version of the stock firmware that you select for the iFaith to create the firmware for.
Then choose ‘Build IPSW’ for your iFaith to start creating a custom firmware using SHSH blobs within for the firmware that you want to downgrade.
Continue your step by choosing Proceed and then Start to get your device into DFU Mode using iFaith’s built-in DFU Pwner (iREB).
Enter DFU mode with the following simple steps:
Press both Power and Home buttons together for about 10 seconds
Release the Power button but keep pressing the Home till you get the blank screen.
You are now in the DFU mode.
Now close iFaith, and then open up iTunes. Choose your device type on the left side menu, and on your keyboard please press the left Shift before restoring to your previously saved custom iOS 5.0 IPSW.