reverting to passwd-less root w/out --skip-grant-tables

[Joe]

I'm trying to get back to an earlier state where we started 
mysqld withOUT --skip-grant-tables but the root user had no 
password.  Yes, insecure, but we're in restoration mode here.

How do I reset/revert the root password to no password without 
running with --skip-grant-tables?

Thanks in advance.