You can manually update a FX-Framework based firmware using the Web UI.
Web UI access is needed to perform the manual update, check FX-Framework Web UI for details.
In any case, you can also use the FX-Framework Rescue System to update the firmware.
Download the firmware to a device that has WIFI capabilities using the Pixel FX firmware download page:
Navigate to http://PRODUCT.local/rescue.html (or http://PUT-PRODUCT-IP-HERE/rescue.html, if MDNS isn't working for you)
Replace PRODUCT with the product you want to update. In case that you're using the IP-Address, replace PUT-PRODUCT-IP-HERE with the IP-Address of the product you want to update.
Although it says rescue.html, this is not the rescue system! (it's just using the same mechanism) No need to open the console and use the button.
Select the xdigital-update.fx file you downloaded earlier and hit the upload button.
Leave Reformat Filesystem unchecked, if you want to keep your configuration settings.
This process is automatic and can take up 5 mins to complete. Once complete, an automatic restart is performed.