|Before you glue the sides and top of the towers down, you may want to make a note of the letter A printed on the tab. Write it on the back of the card so that you'll be able to see it once the tower is glued.
The two towers are assembled like rectangular boxes. Fold the sides around and glue the top down.
Cut out the bottom of the tower and the hole in the center of it. Match the letters in the corner to the letter A hidden inside the tower.
The hole in the center of the bottom piece will help you glue the piece into the right position flush with the bottom of the walls. Use a hooked dental tool or tweezers to pull the bottom out or push it in to match the edge of the walls.