To change the wifi settings on the NOW box to match your new Router.
Then go to Settings from the NOW box, then select Network, then select Set up Connection, then select Wireless, then hopefully from the list of names that the NOW box can see, select the new network name on your new Router and when prompted use the new wifi password off your new Router id label which will be somewhere stuck on the Router (my id label is a sticker on the bottom of my Router).
Should you be using Ethernet rather than Wireless, just select Wired when going through the NOW box Network Settings.
Hopefully then the NOW box will connect to your new Router.
I had a router with a name I knew, and a password that was easy to remember, and to type in, but hard to guess.
Then I had to start using a new router, with a password that I couldn’t remember, but was no harder to guess.
So rather than update 37 devices on my WiFi with these new details, I just changed the details on one device, the new router, and gave it the same SSID and password as the old router.
37 devices then carried on as if the router had never changed, but had just somehow got 12 times faster.