Drop the EMCA repository,sysman schema and objects

[oracle@linux200 bin]$ emca -deconfig dbcontrol db -repos drop

STARTED EMCA at Jun 19, 2013 4:11:49 PM
EM Configuration Assistant, Version 10.2.0.1.0 Production
Copyright (c) 2003, 2005, Oracle.  All rights reserved.

Enter the following information:
Database SID: ORCL
Listener port number: 1521
Password for SYS user:
Password for SYSMAN user:

Do you wish to continue? [yes(Y)/no(N)]: Y
Jun 19, 2013 4:12:28 PM oracle.sysman.emcp.EMConfig perform
INFO: This operation is being logged at /u01/app/oracle/product/10.2.0/db_1/cfgtoollogs/emca/ORCL/emca_2013-06-19_04-11-48-PM.log.
Jun 19, 2013 4:12:29 PM oracle.sysman.emcp.EMDBPreConfig performDeconfiguration
WARNING: EM is not configured for this database. No EM-specific actions can be performed.
Jun 19, 2013 4:12:29 PM oracle.sysman.emcp.EMReposConfig dropRepository
INFO: Dropping the EM repository (this may take a while) ...

ethod 2: Drop the repository schema and object (no quiesce):

Logon SQLPLUS as user SYS or SYSTEM, and drop the sysman account and management objects:

SQL> DECLARE
CURSOR c1 IS
SELECT owner, synonym_name name
FROM dba_synonyms
WHERE table_owner = 'SYSMAN';
BEGIN
FOR r1 IN c1 LOOP
IF r1.owner = 'PUBLIC' THEN
EXECUTE IMMEDIATE 'DROP PUBLIC SYNONYM '||r1.name;
ELSE
EXECUTE IMMEDIATE 'DROP SYNONYM '||r1.owner||'.'||r1.name;
END IF;
END LOOP;
END;
/
SQL> DROP USER mgmt_view CASCADE;
SQL> DROP ROLE mgmt_user;
SQL> DROP USER sysman CASCADE;