Creating a Root User in OS X
To create a root user, go to:
Applications --> Utilities --> NetInfo Manager
Launch NetInfo Manager, then select:
Domain menu --> Security --> Authenticate...
NetInfo Manager - Authenticate
Enter your Admin Username and Password, then click OK.
Unix Admin Username and Password
Domain menu --> Security --> Enable Root User...
You will get an error dialog:
Click OK. You will then get a dialog box to enter a root user password. At the prompt enter your desired password, then confirm it.
For security reasons, it is advisable that your root password be a different password than ones used for other purposes, such as standard OS X admin users or email accounts.
Quit Net Info manager.