here's the customer support page regarding your model router: http://kbserver.netgear.com/kb_web_files/n101210.asp

There are several instructions regarding logging into the router, including resetting the default login/password via the router/vpn firewall reset switch.

For good measure, disconnect the router/vpn firewall from the internet prior to configuring it, to prevent an insecure connection prior to setting it up.