stop and start X server in FreeBSD 9.0

[Istvan Gabor]

Hello:

I configured FreeBSD 9.0 RELEASE with X starting automatically at boot.
I use kdm3 login manager, and it works.
I would like to make changes to xorg.conf and test the effects.
How can I stop X in a terminal temporarily?
If I kill kdm it is restarted immediately.
In openSUSE I could do this by switchiong runlevels but
I learned that FreeBSD has no runlevels.

Thanks,
Istvan