Lift the middle section onto the bottom section. Depending on how big you are, have someone help you lift the large ball. Bend your knees and be sure to stand up with your legs rather than your back. Pick it up and gently set it on the bottom section. Make sure that it sits right in the center of the bottom ball.
- It helps if you flatten the top side of the bottom ball and flatten the bottom side of the middle ball. This helps the middle section sit firmly on the bottom section.