Packages for the release of Plasma 5.2 are available for Kubuntu Plasma5 14.10 and our development release. You can get them from the Kubuntu Next Backports PPA for 14.10, users of the development release will get it as a regular update.
The 14.10 packages include updates to Qt 5.4 which will remove any Unity packages.
To update, use the Software Repository Guide to add the following repository to your software sources list:
Or, from a command line: