Unlockers have been staying away from updating their iPhone to iOS 6 as they will lose unlock. iPhone dev Team released Redsn0w 0.9.15b1 which supports iPhone 4, iPhone 3GS and iPod Touch 4G running on iOS 6 along with the feature to update iPhone 4, iPhone 3GS to iOS 6 while preserving baseband.

We have alreday covered iOS 6 Jailbreak using Redsn0w and downgrade iPhone 4S, New iPad/iPad 3 or iPad 2 using Redsn0w.

In this post we will go through the guide to update iPhone 4, 3GS to iOS 6 without updating baseband.

How to Update iPhone 4, iPhone 3GS to iOS 6 without updating baseband

1. Download Redsn0w 0.9.15b2 for Windows and Mac OS X.

2. Download iOS 6 for iPhone 4 or iPhone 3GS.

3. Launch Redsn0w on your computer by double-clicking.

4. From the main screen of Redsn0w click on Extras >> Even More >> Restore.

5. Click on IPSW button and then browse and select the iOS 6 IPSW file for your iPhone 4/3GS which you have already downloaded.

6. You will get a prompt that Redsn0w can modify the IPSW file to prevent baseband update. Click on “Yes”.

7. You will have to put device in DFU Mode now. Follow the on-screen instructions to put device in DFU Mode. To enter into DFU Mode, hold Power button and Home button both simultaneously for 5 seconds and then release Power button while pressing on Home button for more 10 seconds.

8. When in DFU Mode, Redsn0w will start restoring to iOS 6. Wait till the process gets complete.

9. When done you will get a message that your device has been restored to iOS 6 without updating your baseband.

You have updated iPhone 4, iPhone 3GS to iOS 6 without updating baseband.