How to update KDE on Kubuntu and derivates

With this guide we will see how to update KDE on Kubuntu.

To update KDE on Kubuntu, first you need to enable the “Kubuntu’s backports repository“; as we have seen on the guide “How to manage additional repositories on Ubuntu“, you can either either open the terminal and give the following command:
sudo add-apt-repository ppa:kubuntu-ppa/backports
and then give the following command:
sudo apt-get update && sudo apt-get upgrade && sudo apt-get dist-upgrade
Or you can open Muon (K Menu->System->Muon), select “Source”, “Configure Software Sources”, “Other Software, and then “Add…”; finally insert this line:
deb trusty main
Of course if you are using a version of Kubuntu older than 14.04 Trusty Thar, you have to change the penultimate word of the above line with the corresponding first word of the nickname of the version of Kubuntu you are using (for example ‘saucy’ for Kubuntu 13.10 Saucy Salamander, ‘raring’ for Kubuntu 13.04 Raring Ringtail, and so on).
Once you added the “Kubuntu’s backports repository“, Muon will update its database and it will propose the various updates for KDE; select them and click “Install”.
Regardless if you chosen the command line or Muon, once the updated KDE has been installed on Kubuntu you have to reinitialize your current desktop session: if it has been just a minor KDE update, like from 4.13.1 to 4.13.2, a simple log off and log back in may be enough, but if it has been a major KDE update like 4.12.x to 4.13.x, it would be safe to completely reboot your computer to be sure that all KDE components are reloaded.