In Ubuntu based distros the Xorg config is located at: /etc/X11/xorg.conf
You will need to run a text editor as root, if you're running Xubuntu the command will be...
sudo mousepad /etc/X11/xorg.conf
Run that from the terminal (Menu > Accessories > Terminal
Look through the document for the section that your tutorial tells you to modify.
It is easy to fuck up your X config so you should make a note of the following command. It will let you reconfigure it if it breaks.
@ Smithchild
In Ubuntu based distros the Xorg config is located at: /etc/X11/xorg.conf
You will need to run a text editor as root, if you're running Xubuntu the command will be...
sudo mousepad /etc/X11/xorg.conf
Run that from the terminal (Menu > Accessories > Terminal
Look through the document for the section that your tutorial tells you to modify.
It is easy to fuck up your X config so you should make a note of the following command. It will let you reconfigure it if it breaks.
*sudo dpkg-[I]reconfigure xserver-xorg
*[/I]