You should be will need to do this procedure from ESXI console of the unity connection.
https://supportforums.cisco.com/document/60721/cucm-operating-system-administrator-password-recoveryTo perform the password reset process, you must be connected to the system through the system console, that is, you must have a keyboard and monitor connected to the server. You cannot reset a password when connected to the system through a secure shell session.
Caution The security password on all nodes in a cluster must match. Change the security password on all machines, or the cluster nodes will not communicate.
Caution You must reset each server in a cluster after you change its security password. Failure to reboot the servers (nodes) causes system service problems and problems with the Cisco Unified Communications Manager Administration windows on the subscriber servers.
Note During this procedure, you must remove and then insert a valid CD or DVD in the disk drive to prove that you have physical access to the system.
Procedure
Step 1 Log in to the system with the following username and password:
•Username: pwrecovery
•Password: pwreset
The Welcome to platform password reset window displays.
Step 2 Press any key to continue.
Step 3 If you have a CD or DVD in the disk drive, remove it now.
Step 4 Press any key to continue.
The system tests to ensure that you have removed the CD or DVD from the disk drive.
Step 5 Insert a valid CD or DVD into the disk drive.
Note For this test, you must use a data CD, not a music CD.
The system tests to ensure that you have inserted the disk.
Step 6 After the system verifies that you have inserted the disk, you get prompted to enter one of the following options to continue:
•Enter a to reset the administrator password.
•Enter s to reset the security password.
•Enter q to quit.
Step 7 Enter a new password of the type that you chose.
Step 8 Reenter the new password.
The password must contain at least 6 characters. The system checks the new password for strength. If the password does not pass the strength check, you get prompted to enter a new password.
Step 9 After the system verifies the strength of the new password, the password gets reset, and you get prompted to press any key to exit the password reset utility.
Please rate if you find this helpful.
HTH,
Aeby
Please rate if you find this helpful.
Regards,
Aeby