Re-enabling Administrator Accounts on SBS 2008

Hi
In need of urgent help.
Have a friend running SBS 2008 whereby they recently changed support and in
doing so the new Admin disabled two accounts (the main Admin account and the
Backup Admin account) thinking they were unneccesary accounts only to then
realise the two accounts were the only Administrator accounts.

Apart from two Client profile accounts these were the only four accounts
created out of the box when the SBS was installed. Subsequently no one can
currently log onto the SBS Server as the only two accounts that had log on
rights to the Server have been disabled.

Is there anyway of re-enabling the Admin accounts to regain control of the
SBS server. We can gain physical access to the server and can reboot if
needed.