How to Upgrade Your iPhone 4, 3GS Without Updating the Baseband (Mac)

These are instructions on how to upgrade your iPhone 4 or iPhone 3GS firmware without updating the baseband.

Step One

Create a folder on your desktop called Pwnage

Download the latest version of RedSn0w from here and place it in the Pwnage folder. Likewise, download the firmware you would like to upgrade to from here and place it in the Pwnage folder.

Extract the RedSn0w zip file by double clicking it.

Step Two

Right click or control click the RedSn0w application that you extracted in Step One and click Open from the popup menu that appears.

Step Three

Click Extras from the RedSn0w menu.

Step Four

Click Even More from the Extras menu.

Step Five

Click the Restore button from the Even More menu.

Step Six

Click the IPSW button.

Choose the firmware you would like to update to from the dialog box that appears and click the Open button.

Step Seven

You will be asked if you would like to Prevent baseband update. Click the Yes button.

Step Eight

You will be told that Pwned DFU mode is required. Click the OK button.

Step Nine

Connect your iPhone to the computer, turn it off, and click Next

Step Ten

RedSn0w will now guide you through the steps to get into DFU mode

Hold down both the Home button and the Power button for 10 seconds.

Release the Power button and continue holding the Home button until RedSn0w detects the device.

Step Eleven

Your device will be detected once in DFU mode and exploited with Limera1n. 

Redsn0w will then prepare a restore image.

Step Twelve

Redsn0w will now restore the device to the new firmware.

Step Thirteen

RedSn0w will tell you when the restore has been completed successfully.