Remove the old fabric from your couch and cushions. Write down where each piece came from so you can remember it later. Save the zippers from your cushions if they are still in good condition. These can be reused.
Lay the pieces of old fabric down side-by-side, with the grain or pattern facing in the same direction, and measure how many yards of new upholstery cloth you need.
Lay the old fabric pieces on top of your new fabric and pin them together.
Cut out your new fabric pieces using the old ones as guides for shape and size.
Staple your new fabric pieces onto your couch in the exact opposite order from how you removed the old pieces. Make sure you pull the material taut so your final product does not wrinkle or sag. Use the hammer if the staples do not go in flush to the frame.
Stuff the cushions back into the new covers after attaching the zippers. If the cushions are in poor condition, you may need to cut new foam padding to replace them.