sudo apt-get -y remove --purge xorg-driver-fglrx fglrx* --force-yes
sudo apt-get -y install --reinstall libgl1-mesa-glx libgl1-mesa-dri fglrx-modaliases --force-yes
sudo dpkg-reconfigure xserver-xorg
sudo apt-get -y install --reinstall xserver-xorg-core --force-yes
sudo apt-get -y install --reinstall xserver-xorg-video-radeon
sudo rm /etc/X11/xorg.conf
sudo reboot