The first step would be to unlock the unit. Then you can either reset to factory default or reconfigure it.
To unlock it you first have to figure out what fileserver (FTP server) the unit tries to contact. Therefore you will need a network trace.
Once you have found out the IP address the unit is trying to contact you have to rebuild a FTP server with that IP address and copy a wnos.ini file to that server. The wnos.ini has to contain “Privilege=high” and “Signon=no”.