Downgrade iOS 5.1.1 to 5.1, 5.0.1, 5.0 On All A4 Devices

With the recent upgrade of the iOS firmware to iOS 5.1.1 many A4 device users have been wondering how to downgrade back to iOS 5.1 or lower on the iPhone, iPad and iPod Touch. Apple does however work pretty hard to ensure that users cannot downgrade their devices but thanks to the Dev Team and the Redsn0w tool you can now restore to an older version of iOS 5 in a matter of minutes. If you are looking to downgrade all you have to do is follow this tutorial provided that you have already saved the SHSH+APTicket for the firmware version that you wish to downgrade to. If you haven�t go this you will not be able to follow this tutorial. The first thing that you have to do is download the latest version of the Redsn0w tool. You then need to backup your device�s contents via iTunes or iCloud. Once completed you then need to launch Redsn0w and connect your device to your PC or Mac via USB. Click on Extras, then click on SHSH blobs, then stitch. Select the IPSW to which you want to downgrade to and then point Redsn0w to the .plist file containing the SHSH blobs and the APTicket if you have it stored locally. If you have these files stored in Cydia, the option will be greyed out but will become available to you when the device is in DFU mode. The next step is to put your device into DFU mode, click on Cydia if your files are not stored locally and Redsn0w will save the new stitched IPSW file. Next you need to place your device into Pwned DFU mode. From the main screen in Redsn0w you need to click on Extras then Pwned DFU and follow the on screen instructions. You should then point your hosts file towards Cydia�s servers in order to spoof your device into thinking Apple has authorized the process. If you are a Windows users all you have to do is go to Windows > System 32 > Drivers > etc. On OS X go to etc. Next using any text editor you have to add the following line to the end of the hosts file: 74.208.105.171 gs.apple.com The last thing you need to do is launch iTunes. You need to hold down the left SHIFT key if you use windows or the left ALT key if you use Mac and click on the restore button. Select the IPSW file and restore. It won�t take long to complete and you will be presented with your downgraded firmware. Please note, that this downgrade is only possible on the iPhone 4, iPhone 3GS, iPad 1, iPod Touch 4G and below. This will not work on any of the A5+ devices which are the iPad 2, new iPad or iPhone 4S.