In the players screen, press the blue uparrow button next to player name if available to upgrade the software.
You can find the release notes by following the link in the popup. If a beta release is available you can select the same in the popup at the bottom.
The player downloads the image, prepares for the upgrade and reboots to load new version. If the new version has some issues or crashes, the player automatically reboots & reverts to previous version.