Only the zone creator can delink the root of a zone. The root must not have any objects, descendants, roles, or profiles assigned to it. You must remove all zone guests from a zone before you delink the zone’s root.
You can use the following syntax:
ALTER ZONE zone_name DROP ROOT ;
For information about ALTER ZONE syntax, see Teradata Vantage™ - SQL Data Definition Language Syntax and Examples, B035-1144.