"How do I delete one of the monitors from the setup?"
SaX2 is a nice GUI for editing the file /etc/X11/XF83Config. You can also edit /etc/X11/XF83Config with any text editor such as kwrite. I suggest that you go into /etc/X11/XF83Config with a text editor and remove the description for one of your monitors.
Be prepared. Create a LifeBoat CD.