1. Stop OMS (go to OMS dir)
[oracle@gridrepo bin]$ ./emctl stop oms Oracle Enterprise Manager 11g Release 1 Grid Control Copyright (c) 1996, 2010 Oracle Corporation. All rights reserved. Stopping WebTier... WebTier Successfully Stopped Stopping Oracle Management Server... Oracle Management Server Successfully Stopped Oracle Management Server is Down
2. Config oms password with -change_repos_pwd parameter
[oracle@gridrepo bin]$ ./emctl config oms -change_repos_pwd Oracle Enterprise Manager 11g Release 1 Grid Control Copyright (c) 1996, 2010 Oracle Corporation. All rights reserved. -change_in_db option not specified. Password not changed in backend. Enter Repository User's New Password : Updating repository password in Credential Store... Repository password in Credential Store updated successfully. Bounce the OMS. Successfully changed repository password. If you have multiple OMS's in your environment, run this command on all of them. [oracle@gridrepo bin]$
Or you can also use "-change_in_db" parameter with above command which is optional.
But be aware of prompt will ask you enter existing sysman password. Change sysman password by using tradional command:
SQL> alter user sysman identified by new_pass;