How to cancel the unpaid amount of a Credit memo

Summary:

We need to cancel the unpaid amount of a credit memo which was created in February this year and partially paid in March. Can you please let me know if there is a way?

Content (required):

We need to cancel the unpaid amount of a credit memo which was created in February this year and partially paid in March.

Version (include the version you are using, if applicable):

on 21C

Code Snippet (add any code snippets that support your topic, if applicable):