13.04 - How to uninstall Catalyst 13.8 beta?

I'm currently running 13.04 with the 3.10 kernel, so I can use my wifi.

I foolishly tried to use Catalyst 13.6 beta even though it says it's not compatible with kernel 3.10.

Still, I have my laptop right where I want and can't live without it, but I want to try to install Catalyst 13.8 beta since it's compatible with kernel 3.10.

If the install goes wrong, how can Catalyst 13.8 beta be uninstalled?

Since you built the deb packages yourself, the proper command is:

sudo apt-get remove --purge fglrx*

You missed the "remove" and "--" parts in the previous command you tried. More information can be found here:
http://wiki.cchtml.com/index.php/Ubuntu_Raring_Installation_Guide#Removing_Catalyst.2Ffglrx

If you plan on using the open source drivers after run:

sudo apt-get remove --purge xserver-xorg-video-ati xserver-xorg-video-radeon
sudo apt-get install xserver-xorg-video-ati
sudo apt-get install --reinstall libgl1-mesa-glx libgl1-mesa-dri xserver-xorg-core

sudo mv /etc/X11/xorg.conf /etc/X11/xorg.conf.backup
sudo rm -rf /etc/ati