To connect a new repository is possible the following command in the terminal:
sudo add-apt-repository ppa:graphics-drivers/ppa
Don't forget to disable the repository xorg-the edgers in the Software sources.
Update database of the distribution:
sudo apt-get update
At the end of the update open System settings=>Driver manager, which now shows the new drivers, select the appropriate for you and to install, click Apply changes.
After the driver is installed, you must restart the computer to enable the installed driver.