Yes there is, but it can be quite messy to set up. Google (and search ubuntuforums.org) for "netboot". There's a program which lets you do it from Windows, when I needed to reinstall my mini I netbooted from a Linux server using dhcp3-server and atftpd.
Ubuntu will take AGES to install on the stock (slow) SSD
, so unless you really want to reinstall it would be easier to recover your pass:
Boot up, and when you get to the GRUB screen press ESC to get into the menu. Hit "e". Select the kernel line and hit "e" again. Append "init=/bin/bash" (without quotes) onto the end of the line. Then hit "b" to boot. This will drop you into a root shell, you should now be able to reset your root pw.