Have screwed up my longin and password

[Roger Scow]

I am totally new to FreeBSD, and have installed it and Gnome2/X11.   
Somewhere in the process I have either corrupted or lost my password  
and user name access.  When I try to log into Gnome, either as root  
or as username, it is a no go.

I know that I set up myself as a user, and set a root password when I  
was installing.

What do I do now?  Can I restart from the install CD and go back into  
Sysinstall?

I'm running FreeBSD 6.2 on a Macbook Pro, via Parallels Desktop.

Thanks very much and sorry for such a stupid predicament.

Roger