Try and install Plasma from a live medium provided by several Linux distributions.
Chakra is a GNU/Linux distribution with an emphasis on KDE and Qt that focuses on simplicity from a technical standpoint and free software. The downloadable ISO features a bootable environment that allows you to test the system before installing it.
The Fedora KDE Spin comes with Plasma. New minor Plasma versions are pushed as regular updates for Fedora installations but live media may contain a slightly older release (depending on Fedora’s release cycle).
KDE neon builds Frameworks, Plasma and Applications on a continuous integration system.
You can use the stable version for builds from Plasma/5.x branches or unstable version for builds from master branches.
The user editions build from released software.
Kubuntu 16.04 LTS and 16.10 support Plasma 5.6.5 through Backports.
Alien BOB (Eric Hameleers) provides an installable Live image for Plasma 5 based on the development tree "slackware64-current". Login account/password are both "live". Use su or sudo to become root (using the "live" password).