Hello jpschmidt8, welcome to our community!
You can find the update notes on our Shake OS v0.20 here: Shake OS v0.20 has been released!
Unfortunately, due to the appearance of a serious bug that required an immediate fix from our side, the functionality of changing the network code and/or the station name has been pushed forward to future releases. I cannot, as of now, provide an ETA on this, but announcements will be made as usual as soon as the new releases are published.
Thank you for the notification about the broken link, I have now fixed it. If it still doesn’t work, please hard refresh with Ctrl+F5 (or MAC equivalent) and it should work fine.
And yes, the process is as you listed. You download the inventory file of your station from that link (modifying the station code in the link itself from the base one that is on the manual) and then, on your local SeisComP installation, you can point to this downloaded inventory and the continue with the instructions. It is, for now, the only way to change the station/network code of our Shake models.