If signals of a group have been disabled and are no longer needed in the group, they can easily be removed from the group. Disabled signals in the group tree are greyed out.
To do this, highlight the group in question. If disabled signals are included in this group then the context menu on this group shows the option to remove disabled signals.
Click on Remove disabled signals and the signals in question will be removed from the group.
For information about enabling/disabling signals see part 3, Notes on working in the signal tables.