What do I need to do if I want to change my subscription from Premium to Core?

Thank you for posting, @cindyk1. 

To help you downgrade your payroll subscription from Premium to Core, I suggest reaching out to our Payroll Support team. They have the tools to help in resolving possible downgrade issues due to feature difference. 

You can do it by going to the Help icon at the top right of your QuickBooks Online (QBO) account. Follow the steps below:

1. Go to the Help icon to connect to a live support agent. 
2. Click on the Contact Us button and provide some details about this concern.
3. After adding some insight, tick on the Let's talk button. 
4. Lastly, select the Get a callback button to arrange a call from them.

See this article for detailed guidance: Contact the QuickBooks Online Customer Support team. 

Let me know if there's anything else that I can assist you with. I'm always here to help.