Acquire a box that is longer than usual.
Place it on the stage at an angle so that the extra length is not visible to the audience.
Have your first lady lie with her head sticking out of the box at one end, with her legs curled. This lady is the one the audience will see.
Instruct a second lady to lie at the other end with her feet sticking out of the box, but her body curled inside the box. She should be in place before you begin the trick.
Ensure there is enough space between the two ladies to pass a saw between them, thus "sawing" the lady in half.
Place the box on a table that has a cavity beneath it.
Hide the extra depth of the table with a curtain that hangs from the table top to the floor.
Instruct the lady to lie in the box. The cavity gives her extra depth to be below the top of the table, that is, the path of the saw "sawing" through the box.
Replace her feet with false feet.
Have the feet appear through the bottom of the box.
Withdraw the false feet from the end of a box with an electric motor after the trick is completed, and the lady emerges intact from the box. That way, not only have you sawed the lady in half, but the audience has seen you reassemble her!