Die K Desktopumgebung

4.9 Should I remove old version xyz before installing a new one?

In principle, this is not necessary. RPM and DEP packages should take care of all dependencies.

If you compile the source code yourself, you might take care not to compile different versions of the KDE packages. So if you install a new version, please first make and install kdesupport, then kdelibs, then kdebase.

One thing you should avoid: Installing two (or more, of course) versions of KDE in parallel. This might happen if you specify a different target directory for one version than for the other. The result may be unpredictable. The same is true if you have different versions of Qt installed at the same time. This happens easily if you already have an old Qt version installed with a Linux distribution.