Q: How to change apple ID on Devices

I recently changed my apple ID because it was an email I no longer use, and changed it to my current email. All fine and well.

Then all of my devices requested I sign in with my apple ID. It presented my OLD ID, and of course now I cannot sign in, and use iCloud, iTunes, etc.

I don't see any way in settings on the devices to update to the correct id, and I can't find instructions on how to get the devices to update to the new ID. Help!