October Novel Prep Challenge

The tenth says to write any background story that sets up your plot. Part of the background story to my novel is the prologue of the book, and part has already been written in a story from a few years ago. The story I'm working on in November a sequel.

So my question is this: What should I do regarding that background story that's pretty much already been written except for what will be written in the prologue next month?

Mary

P.S. By the way, the 8th's activity was finished on time, I just couldn't get online to acknowledge the fact.