Users and administrators must be able to view the parent and child to remove a record relationship. They also require Browse permissions and must be in the Removal Group Name, as listed in a record relation definition.
To remove a record relationship:
Navigate to a formal record and select it in the content pane.
Click View > Record Relationships.
Right-click the object listed and select Records > Remove Record Relationship.
If the record has multiple relationships, that is if more than one object is listed, right-click the desired object and then select Records > Remove Record Relationship.