This might not be a good idea tosome users, but I am pretty comfortable logging in as root. As stated on the how-to, you have to enable root. It will ask you for the original password for admin. Then it will ask for root password, then a conformation.
Got to Menu: System --> Admin --> Login Screen Setup --> Security --> Enable root to log into GDM.
That will allow you to log in as root in the login page. Fron there, you are God. So be carefull and know what you are doing before committing changes.
Another safer way is to open the terminal and type:
>su ... then enter you root password.
That will always give you permission to edit all files accessable to root. Ironic ain't it/ You can still bork your install in user environment
If you want the system to ask for a password on every root command do the fallowing:
.... then enter you admin password