@1993ryan
If you don't have access to the old email account you were using to access your Google Nest devices, you will need to perform a factory reset on each device (https://support.google.com/googlenest/answer/9252162) and then reinstall them, since Google Nest does not have any process for transferring Google Nest devices from one email account to another.
This can be problematic on older cameras that do NOT have a factory reset button and can only be factory reset by removing them from the Google Nest app while you still have access to the camera.
