How to edit Menu.lst file?

[aidata]

Just installed K 3.9 on my HD.
I noticed you can't login as root in the normal splash box. I got root access in the terminal, then tried to edit my menu.lst file by: gedit /boot/grub/menu.lst --- this didn't work, so I tried: kwrite /boot/grub/menu.lst --- neither did this. How do you do it? Thx.

[UnderScore]

as a normal user:
kdesu kate /boot/grub/menu.lst

as root user in command line editor:
nano /boot/grub/menu.lst
vi /boot/grub/menu.lst

[aidata]

as a normal user:
kdesu kate /boot/grub/menu.lst

Thnx.