How to turn ubuntu to Kubuntu ?
What we will need to do is to to install entire KDE 4 environment, open the terminal and type :
sudo apt-get install kubuntu-desktop
Now after the installation completed . reboot your PC. then go to sessions and log in into KDE session,
Now open the display manager and change the gdm to kdm using the command :
sudo dpkg-reconfigure gdm
and choose the KDM as a default:
And that`s all :)