Thanks for being a part of the Community, @bookkeeperae.

Instead of changing this payment, you'll want to delete it entirely and create a new one. 

Here's how you'll delete a bill/bill payment check:

1. Go to Transactions, then Expenses.
2. Select Pay Bills Online.
3. Select the Payments tab.
4. Find the payment that you want, then select Track Status.
5. Select Void.
6. Select the void request type:
   • Remit funds back to my bank account
   • Reissue a new payment to the vendor
7. Enter your void request reason.
8. Select Submit Request.

9. On the Expenses page, the status will now show Voided.

Then, you're free to create a new payment with the correct details. 

If you need additional information on getting your new bill set up, you can check out this article: pay bills in Online Bill Pay.

Let me know what else you need help with, I'm only a post away! Take care.