Recently Apple released a new firmware update iOS 8.1.3 for its iOS 8.1.2 running devices including iPhone 6 / 6 Plus, iPad and iPod Touch. The latest update included bug fixes and performance improvements. However, now if you want to get back to older version or downgrade to iOS 8.1.2 for any reason then you can do this by following this guide.
Note: This method will work as long as Apple continues to sign the older version of iOS 8.1.2.
How to Downgrade from iOS 8.1.3 to iOS 8.1.2 in iPhone, iPad and iPod Touch
1. Download the iOS 8.1.2 firmware file for your iPhone or iPad from the below links.
2. Connect your iPhone or iPad running iOS 8.1.3 to your PC or Mac.
3. Launch iTunes on your PC or Mac.
4. Select iOS device from the top right corner.
5. Now while holding Alt key on your Mac or Shift key on your Windows PC, click on Check for Update button.
6. Now select the firmware file you download for your device.
7. Now iTunes will verify the update with Apple to proceed with updating your device to iOS 8.1.2.
8. Click on Update to initialize the process.
9. Now wait until your device is being downgraded to iOS 8.1.2. Once done, your iOS device will restart.
10. After the reboot, you will see “slide to upgrade”, do it, enter your passcode and wait until the process completes.
If everything went right then you should see your device booting the iOS 8.1.2 instead of the latest iOS 8.1.3.