Paint the bookshelves, pegboard, 1-inch by 2-inch boards and extension piece the same color. Allow the paint to dry before you proceed.
Drill pilot holes into the bottom four corners of each bookshelf; attach your casters to the bottom of the bookshelves with their attached screws and hardware.
Lay the two bookshelves together, side by side and shelf side up. Hold a hinge up to the gap between the edges where the two bookshelves meet, about a foot from the top of the bookshelves. Mark the location of the screw holes.
Hold the hinge over the gap again, about a foot up from the bottom. Mark the screw holes. Place a hinge on the center of the edge, and make your markings. Drill into hole locations to create pilot holes, then attach the hinges to the two bookcase edges using the included hardware to connect the two pieces of furniture.
Remove the bottom middle and top middle shelf of the left bookcase to create leg room; set these extra shelves aside. Remove the center shelf of the bookcase sitting on the left. Cut off the back 1-inch of the shelf.
Replace the shelf and then screw it into your armoire, drilling from the backside of the bookcase. Set out one of the extra shelves you earlier set aside and cut off a ½-inch of length. Attach three heavy duty hinges with their included screws to the back edge of this shelf; place one at the left, one at the center and the last at the right.
Connect the unattached ends of the hinges to the fixed center shelf front edge with the included screws.
Cut your remaining extra shelf into five long, equally wide strips. Join these pieces to the front edge of each shelf on the right side of your armoire, nailing through the bottom of the shelves’ edges to create a guard so things don’t fall out when the door opens.
Cut your pegboard to match the top opening in the left side of your armoire. Screw it to the back panel of the left top side of the armoire with the ¾-inch screws, attaching each screw to one of the four corners of the area.
Close your armoire. Place your latch against the edge without hinges, in the center. Mark the holes, drill pilot holes in those places, and then attach the latch with its included screws.