Apple has released iOS 5 for public for iphone,ipad and iPod touch but if you are in iphone then you must know it upgrades your baseband into latest version which will take all the unlock possibility while upgrading iOS 5 but there is a way to get iOS 5 and preserve the baseband with same old baseband to unlock via Ultrasn0w 1.2.4 which has just been released.
How to Preserve iPhone 4 Baseband
The process is one of the easiest ever released so to preserve iphone 4 baseband for iOS 5 upgrade you need is iOS 5 firmware from HERE and iTunes 10.5 from Here and Redsn0w 0.9.9 b5 from Here and follow the steps we have provided .
STEP 1: Connect your iPhone 4 into you computer then open Redsn0w 0.9.9b5.
STEP 2: Now select Extras then “Custom IPSW” option so that you can create your pre-jailbroken custom firmware.
STEP 3: Redsn0w will start cooking your custom IPSW and you’ll get it in few minutes.
STEP 4: Once you get your firmware, select ‘Pwned DFU’ from RedSn0w.
STEP 5: Follow the on-screen instructions to get your iPhone in DFU mode.
STEP 6: Once it’s in DFU mode, close Redsn0w then open iTunes 10.5 downloaded above and you should get your iPhone in Recovery Mode message.
STEP 7: Now hold the Option key on Mac and hit Restore. Point iTunes to your iPhone 4 Custom iOS 5 IPSW which begins with NO_BB. (WARNING: Don’t select the stock one or you’ll lose your unlock)
Since your baseband is now preserved and you are in iOS 5 in iPhone 4 just follow the step Here to unlock using Ultrasn0w 1.2.4
