Make sure your phone is charged with at least 50% battery or is connected to a power outlet
Allow up to 30 minutes or more for the update to complete
Back up your device to avoid losing any data. It is unlikely you will lose any data, performing a back up keeps your data safe incase of any errors.
You will need to be connected to a secure Wi-Fi network (office or home). Update will not work on mobile data.
While the device is updating, please limit its use. Allow time for it to complete the update before using it again.
Scroll down and select General
Select Software Update
Select Download & Install. If no update is available or not showing, first confirm you are connected to Wi-Fi and have enough battery charge. If still no update available, power-cycle the device and then repeat the previous instructions.