There's another thread here with another user successfully navigating this problem:
[SOLVED] Need to access files on computer blindly! Important!
His solution there was pretty difficult, though; he created his own customized boot disk. I think you should try the blind install of openssh-server first. Boot up the computer and log in, then:
- Hit ctrl-alt-f1.
- Enter your username and <hit enter>.
- Enter your password and <hit enter>.
- You could use this command to verify you logged in successfully. It will say "hello" if you're at a command prompt: espeak hello <hit enter>
- Type sudo apt-get install openssh-server and <hit enter>.
- Enter your password and <hit enter>. (Authenticates sudo from above command.)
- Type Y and <hit enter>. (This says yes to "Do you want to continue [Y/n]" from apt-get.)
Then cross your fingers and try logging in from another computer using:
Good luck with it...