You can remotely update your device firmware using Cortex. The firmware updates page shows an overview of available firmwares for the device families that are present in your account. It shows the firmware version, applicable device model, and the release date.
Note that in Cortex, firmwares are displayed separately per inch size within the same device model.
From this overview, you can view the firmware details by clicking the desired version in the overview. From the firmware details, you can also install the update to your devices.