With the two main pieces assembled, apply a small amount of glue to the uncolored side of the floor tabs on the front and sides of the balcony. The tab on the back will be used to glue the balcony to the castle exterior.
Check the direction of the brace on the underside of the balcony floor. You want to make sure it is glued to face the same direction as the braces which are part of the balcony sides.
Glue the tabs to the inside of the balcony along the bottom balcony edges. Use tweezers to make sure the tabs are neatly glued to the balcony sides. Set aside to dry.