Redfin Solutions: How to Override CKEditor Build Config in Drupal 8

Drupal 8 ships with a custom CKEditor build. This build is configured with a build-config.js file. We recently ran into a situation in which we wanted to override this configuration in order to disable a plugin. There is some information in this build-config.js file about replacing it with a non-minified build for development purposes, but nothing about overriding it. Here is how we did it.