How to shutdown KDE from command line?

[Burkhard Perkens-Golomb <burkhard.perkens-golomb@sdm.de>]

Sometimes my X server freezes. I can switch to a text konsole and want
to shutdown KDE cleanly (like a logout from the KDE menu). How do I do
it? Just a kill a process (and which one)? Another way?

Thanks,

        Burkhard