How to get out of KDE

Hi, I use mate and openbox in TW, and thought I'd have a look at KDE. So I installed KDE as described here: https://en.opensuse.org/SDB:KDE_install However, my display manager, lightdm, has now been replaced by KDE's display manager, SDDM I believe, with which I can only log into KDE. So I'm stuck with KDE! In YaST's sysconfig editor, Desktop > Display manager, everything is greyed out. In /etc/sysconfig/displaymanager, if I add 'DISPLAYMANAGER=lightdm', it has no effect. So how could I still log into a window manager other than KDE?