It's not clear about what password You say.
1. ALOM username/password. Can be clear from Solaris via scadm
2. OBP password. Setting via variable OBP security-modesecurity-passwords
You can't clear it in case security-mode full and You don't remember password. You need replace configuration card.
3. Solaris username/Password. For clear root password - boot from install media.
Thanks for the Reply
i am not able boot the machine itself. i have tried all the steps. To recover the Password of the Firmware.
I am not asking about the root password. and I am saying about the OBP password and how to change the configuration card for the V440