substitute a schema

Hi Guys

I develop a simple schema and now I would like to suibstitute the actual schema for another one with same attributes and objectclass + another attibutes and obcejtclass .

See its a superseed of ther previus one...

I have already try using : ldapdelete -Y EXTERNAL -H ldapi:/// cn={6}squid,cn=schema,cn=config but received a: ldap_delete: Server is unwilling to perform (53)

Doing it by hand it worked ( stoping ldap, substituted cn=squid with new one and restarting ldap), but I know that is not correct...

How can I do it using ldapdelete ?

best regards