1) Start the updater app
Click on the "All apps" icon, and then the "Updates" entry
2) Locate the newest firmware
Click on the "Refresh" button to ensure you have the latest firmwares listed.
Find the latest firmware and click on the "Download" symbol to the right.
Wait for the firmware to download.
3) Install the update
Click the "Update" button and the device will reboot, install the update, and then reboot again.