Attach the five 4 ft. 2-by-4s to the five 1-ft. 2-by-4s using the screws and the power drill. They should be in a perpendicular fashion. When this task is complete, there should be five large L-shapes. Set these to the side when finished.
Gently break down the cardboard boxes without ruining them. Cut them all into flat sheets using the box cutter. Tape the cardboard boxes together with the duct tape until the desired size is achieved. Use the box cutter to trim the edges for an even look. Also cut openings for the actors to enter and exit the stage, if necessary. When this task is complete, the boxes should resemble a huge, flat wall.
Spread the five wooden pieces across the back of the cardboard structure on the side where the duct tape is visible. The four foot sides should be against the surface of the cardboard with the one foot side sticking up. Attach these pieces to the cardboard with the screws and the power drill. Stand the cardboard wall upright with the one foot side of the wood pieces laying flat on the floor. Place two bricks on each of the wood pieces to hold in place. The cardboard wall should be standing on its own now.
Lay the paint tarp down to protect the floor. Open the primer white paint and pour it into the paint pan. Apply two solid, even coats of white paint to the front surface of the cardboard. When this is finished, there should be no visible traces of the color of the cardboard. Allow time to dry. When the paint is dry, decorate the backdrop as desired.