I am under Gnome. At the install I have + openbox and xfce.
How change Gnome in openbox or xfce ?
On Gnome I can’t change user or deconnect !!!
Have you tried this page first: Arch Display Managers?
You’ll either have GDM or LightDM.
Sorry, I have kill Gnome and it’s ok…
I agree with @DatNobleSavage, If you don’t already have one installed, by installing a login manager, you will have options to pick the DE/WM you want to login to from the gitgo without any extra commands like kill or moding an .xinitr file etc.
If you do have a login manager, you should be able to pick you options at bootup or on login.
I don’t recall for GDM but LightDM gives you the option in the upper right corner.