change database id of database

SQL script to change database id of database.
. oraenv
sqlplus / as sysdba
shutdown immediate (shutdown abort if need)
startup mount
host nid target=/ (tesed, why it hold here?)
--OR
--exit
--nid TARGET=system/password
--sqlplus / as sysdba
startup mount (shutdown abort if need)
alter database open resetlogs;
select dbid from v$database;
 
http://remidian.com/oracle/change-database-id-of-database.html
fyi,1) login as "oracle"

. oraenv

 input sid

 2) sqlplus '/as sysdba'

   SQL> alter user system identified by "yourpassword";

 alter user sys identified by "yourpassword";

alter user system identified by "yourpassword";

alter user dbsnmp identified by "yourpassword";

alter user sysman identified by "yourpassword";

grant sysdba to system;