In order to execute this just curl and redirect output to bash (url to raw may change):
curl -o- https://gist.github.com/raw/3406323/f95c4f08ced19afbd9f1fa56198f5596693a8361/Atheros-AR8161-install.sh | bash
This is now in backports (for Ubuntu at the least):
sudo apt-get install linux-backports-modules-cw-3.6-precise-generic
sudo modprobe alx
This package may also be available in higher versions - >=3.6 so check the repos first.
For Debian you can search for alx in the repos.