I use this book for 2nd graders and taught from it last year. I agree, they're terrible, but here's some tips:
Definitely get the teacher's book. Ask your coteacher for one. It's a big blue book that outlines the grammar points/expressions for each lesson.
Give the lessons structure so the students aren't confused with too many changes from week to week. My basic structure is this: Introduce the grammar point or expression, then we get into the book work. They listen and answer the questions, and after each section we practice the dialog chorally. Then they practice with partners, then they volunteer to read with their partner in front of the class. Rinse and repeat for each section until you finish the book work. After the book, we always have an activity or game to focus on the point of the lesson.
The activity section is very dry for this book, IMO, so add some sort of game or activity at the end to focus on the point of the lesson. Even if you have to stick to the book, there is NOT a lot of material to get through. We finish the bookwork in less than 20 minutes, usually. This can be anything from having students create their own dialogs to preparing a PPT game, or anything in-between. For lesson 1, I'm going to make an activity using the "Pass the Pencil" template where they will practice "Long time no see" and "Do you remember...". I'll post it when I'm finished in case anyone wants to use it.