Absolutely, admin can reschedule a specific installment within the payment plan of a customer from the Back-End of Partial Payment Extension for Magento 2.

Read this guide on How to Sell Products on Installment & EMI in Magento 2 Website to reschedule a specific installment from back-end using this extension.

Here are the few more resource to help you get most out of this Magento 2 Partial Payment and Layaway & EMI Extension.

• What are Layaway and Partial Payments? How is it Beneficial for Businesses and Customers
• Drive Customer Loyalty through Layaway & Partial Payments
• How to Reduce Abandoned Carts with Partial Payment Extension
• Enhance the Customer Satisfaction Rate with Partial Payment Extension