In some situations, you might want to disable a D-Bus service. One of those is, for example, when you use Dunst (a notification daemon) with a window manager. Still, you don’t want it to replace the notification daemon from your desktop environment.
To disable it, you just need to add .disabled to the end of the target file name. Example:
sudo mv /usr/share/dbus-1/services/org.knopwob.dunst.service /usr/share/dbus-1/services/org.knopwob.dunst.service.disabled
In the above example, Dunst will no longer replace Plasma Desktop notification daemon when using that amazing desktop environment, and all will be good with the world again. Victory! :)