I imagine you're booting with a Live disk? As long as you don't restart, everything that's been downloaded will be saved for now, so, once you log in, just re-enter the commands, won't take long to do this time around, you might not even have to re-enter them all, but I did it anyways just to be safe.
Open terminal, enter "sudo passwd root". That'll reset the root password so you can actually log in to root, then just log out of your current user, and log back in as "root" with a blank password.
Then, re-enter the commands and voilla! Should work bulletproof.