For vehicles with an Onboard Computer running BlueOS, and an IP-based (wifi / ethernet tether) connection to the Control Station Computer, Cockpit is available as a BlueOS Extension.
Once installed, updating to a new Cockpit version can be done via the "Installed" tab of the BlueOS Extensions Manager.
In future, Cockpit will also be available as a self-contained Electron application, which can be stored on a Control Station Computer and started up for connection to a vehicle.