What exactly is the problem?
If you are able to switch from X to a text console (using Ctrl-Alt-F1 through F6), you can, as root, run the command
# init 3
to change to text only mode and then
# init 5
again to revert back to X.
If you do not want your system to boot into X, you can edit the inittab file and change the initdefault setting to 3 to boot only into text mode.
If you want X, you can either do an init 5 or use the startx command.
It is a good practice (I feel) not to run X by default if a Linux system is being used as a server.