Step 1: 123d Make
1) up to the upper left hand side click File--> Open example-->Rocket. You can also import your own CAD file or browse the online Gallery that has ton's of models to pick from.
2) To toggle the view of your model use your right mouse button, to Zoom in and out use your scroll wheel.
3) Choose a Construction Option- for this project I choose to Radial slices.