Method 1: official recovery
Downgrade description:
This method is applicable when the latest iOS8.1 system verification is not disabled
Procedure:
1. Connect the iphone, ipad, iTouch, and other devices to your computer and open iTunes.
2. Press Shift on the keyboard and click restore in iTunes with the left mouse button.
3. A dialog window will pop up in iTunes, and then select iOS 8.1 firmware (download)
4. To successfully recover iOS8.1, you must activate the device (follow the system prompts to complete the steps ).
Method 2: DFU mode recovery
Downgrade description:
This downgrade method requires entering the DFU mode or recovery mode, which will erase all the information on your device. Therefore, you need to back up the device in advance.
Procedure:
1. After the iPhone is shut down, press the Home key for 8 seconds to connect to the computer through the USB data cable. Alternatively, connect the device to the computer. Press and hold the power key for 3 seconds, and then press and hold the switch key and Home key at the same time, when it lasts for 10th seconds, immediately release the key and hold down the Home key until the DFU mode is displayed on the computer, at this time, iTunes will be started automatically or manually.
2. iTunes automatically detects a device waiting for recovery. Click OK.
3. Press the shift key on the keyboard to "restore" on iTunes and select iOS 8.1 firmware (download)
4. The device will start to flash the machine again and restore it to a brand new system.
5. After the recovery is complete, click "set as a new device" on iTunes ".
Now, we have finished the tutorial on downgrading the ipad. The above reference figure is an example of iPhone 4S.