Install KDE Plasma Desktop 5.8.5 in Ubuntu 16.04, 16.10

The latest KDE Plasma Desktop 5.8.5 was finally made into Kubuntu Backports PPA several hours ago, available for Ubuntu 16.04, Ubuntu 16.10 and derivatives.

Plasma 5.8.5 is a bug-fix release for the 5.8 LTS series that features:

• Notice when the only screen changes.
• Revert ‘Do not ask for root permissions when it’s unnecessary’, it caused problems with adding a new user.
• Fix compilation with Qt 5.8.
• See the full changelog of Plasma 5.8.5.

How to Install / Upgrade to Plasma 5.8.5 in Ubuntu:

1. Open terminal emulator from App Launcher and run command:

sudo add-apt-repository ppa:kubuntu-ppa/backports

Type in password when it prompts and hit Enter.

2. Then a full system upgrade will bring the current Plasma desktop to the latest (need restart):

sudo apt update

sudo apt full-upgrade

How to restore:

To undo the installation and restore to the stock version of Plasma desktop in Ubuntu 16.04/16.10, run command to purge the PPA repository:

sudo apt install ppa-purge && sudo ppa-purge ppa:kubuntu-ppa/backports

The commands will remove the PPA and downgrade all installed packages from that repository to the original versions.