[S.u.S.E. Linux] How to set a different WM?

Hi! I am a new user of Linux and S.u.S.E having just installed it yesterday. Now I am trying to find a way to change the default Window Manager to KDE. Could someone tell me which file should be changed and how? Also what should be done when I want to upgrade the version of KDE to a new one? Thank you in advance for your help. -- To get out of this list, please send email to majordomo@suse.com with this text in its body: unsubscribe suse-linux-e