Volumes can be removed from an assigned container from the volume inventory window, container inventory window, container properties window and automatically via repository property options.
Volumes can be deassigned from a container from the perspective of selecting the volumes and then removing them from a container, or selecting a container and then removing the volumes.
Selecting volumes and removing from a container
Selecting a container and removing volumes
Volumes can also be automatically deassigned from a container triggered by confirmation of a container move from one repository to another.