You can remove a payment plan from an existing order by following the steps below.
  1. Use search field on the top right side to find customer by order number or by customer name. 
  2. Click customer name
  3. Under Order history tab, click desired Order number 
  4. Underneath Make a Payment button, click Remove Payment Plan
 
  1. Follow prompts
  2. Click Submit
Note: Once the payment plan is removed, all remaining balances appear on the order and the customer can manually pay it from their online account

For additional information about adding a payment plan, use the article: Add Payment Plan to an Existing Order