Wifi extender already named & associated with username - unable to setup

I just bought a wifi extender from Target, got home to set up and it is already named "Kroger Guest_EXT." When I click on that it brings up the netgear page where the instructions tell me to create a new username so I can set it up with my wireless router. I CAN'T do this, though, because there is only an option to log in or get help with my password. I guess it was previously used and set up, then returned. I can return it I guess but I was hoping there might be a fix I can do at home so we can start using it today. Any ideas??