one thing you can try; all the passwords are stored as MD5 hash
in the smcinstdata key ;
say if you want to set your new password "Rafeeq"
to to online md5 converters; get the MD value
all you have to do is to replace the key as per this document..
you can run a script to do that.
https://www-secure.symantec.com/connect/articles/how-uninstall-symantec-endpoint-client-if-uninstall-password-place