Beside BIOS update, you can also download the driver update files from that website as well.
The BIOS update is pretty straightforward. Make sure that the battery level of the laptop is at least 80%, and it is plugged on to the AC power supply. Then, run the BIOS Update Utility.
The new BIOS will be flashed with the InsydeFlash utility from Windows 8.1. After that, the system will reboot itself, and the BIOS update will be performed.
You will eventually reach to a state that the keyboard backlit of the laptop is on, and the screen is blank. Wait for a while, then long press the power key of the laptop to switch it off. When you switch it on again, the new BIOS is now up and running.
There is no data lost for this BIOS update. Even the BIOS settings and passwords remain after the update.