Here are the steps to connect your system to a new router/WiFi network…

https://support.sonos.com/en-us/article/connect-sonos-to-a-new-router-or-wi-fi-network

It’s been a while since I changed my router, but I chose the wired option instead and then later switched things over to the new wireless credentials, which is mentioned in the second part of this Sonos article…

https://support.sonos.com/en-us/article/switch-sonos-between-a-wireless-and-wired-setup

Hope the above two links assist you to swap to the new router WiFi network, whichever way you decide to go about it.