Pop up Animation

In this animation I was attempting to create a pop up style animation. I created the images in Illustrator and then created the animations in After Effects.
The characters took a while to create and I like how those turned out. But I'm not too crazy about the animation part of it. I wasn't sure how to adjust the pivot point on the images so that they rotated around that instead of in the traditional middle point. I should have looked it up and figured out how to adjust that point to make the pop up animation look for like a pop up book.