Once the boxes are lowered to the ground start inserting the blades in their places

Then open the doors of the top four boxes to reveal the body of your up side down assistant- you will notice that her dress had fallen down because of gravity and that's why it's important to choose a volunteer with the right kind of dress for the illusion -and u can see the blades dividing her body to 5 parts with her head hiding in box 5 that remained unlocked