Step 2.
Lay out the left (or right) rear axle and wheel assembly. Slot the wheel assembly into the black axle making sure to line up the "clevis" pin holes. Secure by sliding the "safety snap pins" through the holes and clipping the security holding device (attached to the pin) into place to prevent the pin from falling out. You do this with all the pins. Slide the axle with wheel assembly into body, slide in securing pin again snapping the security holder over the end of the pin. You will do the same with the other assembly on the opposit side.