I. Place the backrest with legs (#1) on a protected surface. Align the seat (#2) with the pre-drilled holes of the backrest with legs (#1). II. Prepare a bolt assembly by inserting FIRST the lock washer (#D) onto the bolt (#C) and then the flat washer (#E) onto the SAME bolt (#C), in that order. III. Insert the bolt assembly through one of the pre-drilled holes in the center of the seat (#2) and secure the bolt using the Allen wrench (#F) to lock it with the backrest with legs (#3).