@Scott6693
Unfortunately, Google Nest does not make it easy to update Wi-Fi settings on its cameras and doorbells. That's why their first recommendation is to use the same Network name (SSID) and password on your new router/modem as you used on your old router/modem. That's what we did, and we did not have to update any of our Google Nest devices.
If you can't do that, then the general process is to remove your devices from the Google Home app (and/or Google Nest app), hopefully while you are still on the old Wi-Fi network and your devices are still online, thereby also triggering an automatic factory reset. If you can't do that, then you need to do a manual factory reset on each device (see the link in the post below, and make sure to use the "Factory reset" instructions, NOT the "Restart" instructions). Then you'll have to reinstall your devices in the Google Home app (and/or Google Nest app).
https://support.google.com/googlenest/answer/9223711
