Registering a modem purchased used and has previously been activated

I recently purchased a used router and have done a factory reset on it.  I am able to connect with the default name and password, but would like to perform a setup to create my own password for better security.  I started going through the wizard setup, but when I tried to create an account, it said the device was already registered.

Is there any way I can get the device assigned to me now?

Thanks.