Place drop cloths on the ground to protect the surface. Set the furniture on the drop cloths.
Clean the black furniture with a damp cloth to remove dust and dirt. Wipe the furniture with a dry cloth.
Scuff the furniture with 180-grit sandpaper. Sand the furniture by hand or use a handheld sander if you're working on a large piece of furniture. This prepares the furniture to bond with the glaze and paint.
Apply the red glaze with a paintbrush. Brush the glaze on heavily, and wipe the glaze away with a damp cloth. Start at the top corner of the piece and work in small areas. For example, on a chair, brush the glaze over the seat, and wipe the glaze with the damp cloth. Then work on the arms, then the legs, and so on.
Paint on one to two coats of clear, water-based top coat to seal in the new brownish color.
Wipe down the black furniture with a damp cloth to clean off dust and grime. Wipe the furniture dry with a clean cloth.
Place drop cloths on the floor. Set the furniture on the drop cloths.
Sand the furniture with medium grit sandpaper. Go over the entire piece to scuff off the top coat of paint. The 180-grit sandpaper works well. Sand the furniture by hand or use a handheld sander.
Prime the furniture with spray primer. Spray in even strokes to cover the entire piece completely. Let the primer dry four to six hours.
Apply the brown gel stain with a paintbrush. Spread the stain evenly. Wipe away excess stain with paper towels. Work quickly because the stain dries fast.