In iPad mini3, open the [general] option in [Settings] and click to enter, and then find [software update] (we 'd better download and upgrade on the wifi network ).
It takes some time to update the status Detection. After checking the status, you will see the ios8.1.1 system as shown in the following figure. Click the download and install button and then click a agree clause.
Then, click download and install next to it to download and install it.
If the iOS device sets a boot password, you need to enter a boot password.
After the firmware is downloaded, click agree or cancel.
To upgrade the system, you must click the agree button.
The system will verify and install the new iOS8.1.1 online.
After an online upgrade, you only need to restart your mobile phone and do not need to activate it. The data in the device is fully preserved and will not be lost due to the upgrade.