There is 2 way to reset the password.
First is you can click the forgot password.
Password will be sent on email which is configured.
Second way is to resetpass.bat tool
For Resetpass.bat tool you can contact with symantec technical suport. They can share you.
After run the batch file password will be admin.
Below article will assist you on the both of the cases.
https://www-secure.symantec.com/connect/articles/how-reset-symantec-endpoint-protection-manager-console-password-sep-121