Deleted root account in passwd

["Pete Clarke" <pete@dynotechnic.co.uk>]

Hi there,

<dumb mode>I managed to delete the root entry in /etc/passwd whilst playing 
on a test box</dumb mode>
Is there an easy way of re-inserting, or copying the backup passwd file I 
have without physical access to the box?

I can ssh into it, but only as a regular user - obviously I can't su to root 
as it doesn't exist anymore :-)

Any ideas?

Cheers