You have completed quite a bit of analysis on the chapter you chose to focus on, and you have come up with a plan for how to improve the chapter. So now, using that information you will create the revised chapter based on the recommendations you presented. You do have the option if you prefer to create a different chapter. It could be a chapter for the zombie guide that focuses on a different topic, or it could be a chapter that has nothing to do with zombies. It would, however, still have to be a chapter for a survival guide. I will be able to provide you with the original chapters so you can actually work from those, as opposed to starting from scratch.
The chapter should be created in .doc format, but when you submit it you should save it as a pdf file if possible. When you deal with this kind of text document with lots of images it will transfer much better if sent as a pdf.