KDE SC was released a few days ago and I have already upgraded my openSUSE and Arch machines with it. That left my Kubuntu box behind which I updated today. It’s as easy to get KDE SC 4.12 on Kubuntu as it was on Arch or openSUSE.
Open terminal and first add Kubuntu Backport PPA to your system:
sudo add-apt-repository ppa:kubuntu-ppa/backports
Hit Enter key when asked to import public key
Then run this command
ssudo apt-get update
sudo apt-get upgrade
You can read more about KDE SC 4.12 here to know what’s new.