John N. Alegre wrote:

Is there a way to ssh login from a remote machine as some user and kill the X server for a that user?

john

Of course there is. Login as root per ssh and type 'killall X'. Or type 'init 3' to switch to runlevel 3. It is without graphical login and will kill all X stuff. The normal runlevel is 5. 6 is shutdown ... + N.Eschricht