Hello, if the version is V100R005C30SPC700 , and forget the password of the admin, you can do with below step:
1, connect to the controller by serial cable.
2, login by user "_super_admin", and password is "Admin@revive"
3, input command "initpasswd".
4, input "exit", it's end.
if it doesn't work, please tell us in which step you failed? it will be much better if there is screenshot.