I screwed up the lightdm.conf file as superuser.
What I was trying to do: I tried to insert a command (xbacklight -set 50) that sets my monitor brightness at the lightdm config file. Now when I start my laptop, it gets stuck at the xubuntu loading screen, so I can't login.
Is there a way to go into the shell/command-line and fix the lightdm.conf file??