Once xtrekd is running, players can connect to it by running xtrek with the machine name the daemon is running on as the argument on the command line. For instance, assume that a player has a running xtrekd on ligonier.andrew.cmu.edu. Then
xtrek ligonier.andrew.cmu.edu
would send a request to the daemon on ligonier to open an xtrek window on the local machine. Various errors can occur at this point, most of which have to do with access protections on your X server - you must first xhost to the machine running the daemon.