The Release Manager can unlink a child release record using the following steps.
To unlink the current release record from a parent release record
In the Service Manager console, open the Work Items workspace, and in the Work Items pane expand Release Management.
Select any Release Management view that contains a child release record that you want to unlink from its parent release record.
In the Tasks pane, click Link or Unlink to Existing Parent Release Record and then in the fly-out list, click Unlink.
In the Comments box, type a comment indicating that you have unlinked the child release record from its parent release record and then click OK to close the Comments box.