On Friday 20 March 2015, Gene Heskett wrote:
> password.  But the only way to get rid of a root password is a bare
> metal reinstall.
>
surely not. I don't know the answer by heart, but editing in /etc/passwd 
or /etc/shadow, or other files for sure gives you the possibility to get rid of 
the password. 

Here seems to be an answer to your question:
http://www.debianadmin.com/enable-and-disable-ubuntu-root-password.html

In short:
--- snip ---
If you want to disable root account in ubuntu you need to lock the root account 
by using the following command

$sudo passwd -l root
--- snip ---

I've not tested it though

Gerhard