Lay sections upside down on cardboard or other non-scratching surface.
Locate the legs where marked on the underside of the deck sections. Unmarked legs are used in the center of each section.
Insert the smaller (5/16th) dowels in the holes in the deck sections, making sure the letter designations match on the leg and the deck.
Attach the legs by running screws through the leg into the underside of the deck. Only screw one side of the dowelled legs. Attach leg braces.
Set sections 4-9 in place, then 1&2. Slide step sections in place and mark their location. Lift out the steps and the sections they rest on, and secure the steps to the sections by running screws up through the section into the step.