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

Unplug your Play 1 and other Sonos gear. Delete the Sonos app from your device. Setup the new network gear supplied by your new ISP using the same SSID and Password as your previous network gear. Once setup connect your device to the network. Plug-in your Sonos gear. Wait 5 - 7 minutes. Download the Sonos app and when prompted select “Join an existing system”. You should see your Sonos. You’ll have to sign in again.

Or… you can follow the advice given by ​@nik9669a .