If you are using iCloud Photos, you would need to sign out of the Apple ID on a device, iPhone, iPad or Mac, and when asked wether to keep the photos answer yes. Then when signing into the new one, you would need to turn on iCloud Photo Library in settings for the saved photos on the device to sync to iCloud again.
If not using iCloud Photo Library, then you don't need to do anything as the photos would be locally stored on the device.
With that said, are you sure the can't be removed? And why is that a problem? Where are these email addresses exactly?
If you follow the steps in the support document you posted from can you not see and remove the addresses from there?