[CentOS] how do I stop X / gnome via SSH?

>> I need to disable / stop X from running on a remote server, to which I 
>> only have SSH access, and I have never done this before. So, can 
>> someone please tell me how todo it?
>>
> telinit 3

If you need the server to stay at runlevel 3 after a reboot
change id:5:initdefault: to id:3:initdefault: in /etc/inittab.
Make sure the required services are enabled at this runlevel.