I forgot my password to the root account, I have autologin enabled so I can use it, but unable to make changes in it. After searching and searching I found a "solution" which does not work for me at all.

I open "Advanced settings for Ubuntu" and choosed Ubuntu with Linux generic 3.8 (recovery mode), choosed root, and entered

mount -rw -o remount /

but it doesn't work, it shows "help" about mount (mount --make ; -o [options] [passwdfd] and so on), but not what it was supposed to do. Tried again and again but still nothing. I get the manipulation token error if I try to ignore the mount stuff.

Has anyone any advice or suggestions on how to fix this, please?