Totally remove Unity from Ubuntu 12.04 Precise

This guide is for all those who, like me, appreciate Ubuntu but just can not digest the new license plate interface Canonical, Unity, For all those who are not content just to install another DE and select the login, but they also want eradicated from the system every single package, track and dependence of Unity. I do not want the passionate fans of Unity, have patience, are bastard (and picky). So:

We proceed to install Gnome Shell, his Account Manager (who will replace LightDM), good old Synaptic package manager and as a utility that will allow us to clean it up, in this case, each "residue" of Unity.

Open a terminal and type:

sudo apt-get install gdm gnome-shell synaptic deborphan

During installation you will be asked to set the default Login Manager, select "gdm" and continue. Reboot the system to log and choose "Gnome". We open the terminal and proceed to the removal of Unity in all its components, or open Synaptic and manually select the packages to remove:

sudo apt-get remove unity unity-2d unity-2d-common unity-2d-panel unity-2d-shell unity-2d-spread unity-asset-pool unity-common unity-lens-applications unity-lens-files unity-lens-music unity-lens-video unity-scope-musicstores unity-scope-video-remote unity-services indicator-messages indicator-status-provider-mc5 appmenu-qt appmenu-gtk appmenu-gtk3 lightdm unity-greeter overlay-scrollbar zeitgeist zeitgeist-core zeitgeist-datahub activity-log-manager-common activity-log-manager-control-center

Then type:

sudo apt-get autoremove

Now we proceed with the removal of all packages "orphans" who have remained in the Unity system with deborphan with:

sudo apt-get purge `deborphan`

We repeat the command several times to remove even the dependencies of dependencies, until we answer that there are more packages to be removed.

And finally, we eliminate even the small configuration file of Unity remained, by typing:

sudo dpkg --purge `dpkg -l | egrep "^rc" | cut -d' ' -f3`

We will then have a clean Ubuntu 12.04 and distilled, with only Gnome Shell.