How to downgrade IOS Firmware

Downgrading your iOS Firmware

If  you updated your iDevice to a firmware that is not jailbreakable and want to have an untethered jailbreak a great solution is to downgrade your iDevice to an untethered jailbreakable version…
(NOTE: You have to save your SHSH at Cydia first….)
Here is the proccedure:
1-Download the iOS Firmware that you want to downgrade to.     NOTE: the .ipsw file that you should download must correspond to the iDevice that you want to downgrade.   (links below….)
2-Find the hosts file at your system:
      Mac:  /etc/hosts 
      Windows:  c:\windows\system32\drivers\etc\
3-Edit using the Notepad on Windows or Text Edit – or Terminal (sudo nano /etc/hosts) - on a Mac

– If you use the Text Edit on a Mac you should change the permissions of the file so as you can edit it ( cmd+i ) and make the appropriate changes by unlocking the lock on the bottom.

Type at the last line: 74.208.105.171 gs.apple.com

4-Enter DFU mode
5-Open TinyUmbrella and press “Start TSS Servers”
6-Now open iTunes and go to your iPhone
Press SHIFT+Restore on a Windows, and opt(alt)+Restore on a Mac and browse to select your ipsw you want to downgrade to and click on Restore when the Pop-up shows-up.
6-Leave the Rest to iTunes
Note: If iTunes shows an error don’t panic! iTunes have installed the firmware you chose to downgrade to and has put your iDevice in Recovery mode.  (To kick out recovery download TinyUmbrella, choose your iDevice, and click on the “Exit Recovery“)

Now you are able to jailbreak your iPhone in an untethered state!

Links:

• Download any iOS Firmware Version: http://www.limera1n.cc/p/download-ios-ipsw-firmwares-files.html
• TinyUmbrella: http://thefirmwareumbrella.blogspot.com/

• How to enter DFU Mode?

Now you are able to untethered jailbreak your iDevice (the iPad 2 is only jailbreakable on 4.3.3 using Jailbreakme 3.0)