Need help registering product (product already registered)

I had bought one of these a couple years ago brand new. well i ended up started a business with a friend, and long story short the business fell out but the router was so intertwined with it i told my partner he could keep it if he got me another one, he did get me another one but it was either refurbished or used and now i am unable to register my product, i checked the community and all signs point me towards @Christian_R, @ChristineT or @DexterJB  please help if able to. Would appreciate it greatly.