Dedicated server files can be installed via SteamCMD (app id 2430930) but it seems you must use a Steam login instead of remaining anonymous. Slightly irritatingly, you also have to have a Steam client logged in on the server host machine. If you play from a client on a different machine, an error message pops up on the server host asking you to exit Steam. If you ignore it, the server continues running. Anyway... It's taking a full 16GB of RAM but it's running!