Download the firmware image from https://files.zubax.com/products/com.zubax.telega/firmware. You can use your preferred firmware image if you have one. If you are using v0, then the file extension must be .application.bin. Using .compound.bin will not work.
Download Yukon for your OS:
Start Yukon; in the Settings, find the firmware update section and ensure the path points to your downloads folder.
Select your CAN adapter in the Transports pane, then click “Start this transport”. Online Cyphal nodes, if any, will appear in the large Monitor panel.
Find the node you wish to update and click “Choose firmware”, then select the firmware file you downloaded in the first step. Repeat this step for all nodes that need updating.
Unattended automatic firmware update can be performed using the Yakut CLI tool, but there is a bit of an entry barrier. Refer to the README for details: