How to Downgrade iPhone 3.1.3 firmware to 3.1.2
In this how-to video, you will learn how to downgrade an iPhone or iPod Touch to 3.1.2. First, download the correct firmware model. Hold the home button and power button. Release the power button when the screen turns off. Make sure the device is plugged in while doing this. This will put the device in recovery mode. In iTunes, hold shift and click restore in the device screen. Next, navigate to the firmware you downloaded and click okay. This will downgrade the device to the firmware you downloaded. This will take a while. Once this is done, you can check the version on the iTunes screen. Viewing this video will show you how to safely and properly downgrade your iPhone or iPod Touch to an older version.