Switch to a different tty uing ctrl+alt+Fx (F1 to F7).
Log in as the normal user and then su or sudo to the root account.
THe output number will be the process to kill.
Get on another computer and look up reconfiguring X11.
Switch back to the thinkpad and type
kill <process of display manager>
From the command line, follow the directions for reconfiguring X11.
Exit to the normal account and type
to test the output.
You can also use google to find if anyone has a configuration for your machine.