Remove the old fabric from the couch. Slide a utility knife along the seams to cut them and pull off the fabric. Look for any staples the manufacturer used on the fabric. Slip the edge of the pliers under each staple and pull up until the staples peel off the wood. Keep pulling off the fabric until you expose the couch down to the original wood and metal frame.
Unzip the couch cushions and remove the cover from each one. Wrap the old covers with new pieces of upholstery fabric, laying the fabric directly on top of the cover. Slip sewing pins through the edges, creating the outline of your seams. Run the pieces through a sewing machine, stitching closed the new seams and cut off the excess fabric. Remove the pins.
Turn the covers inside out, so that the patterned design faces up. Attach a zipper to each cushion with sewing pins pushed through the edges of the fabric on the zipper. Stitch along each side, firmly attaching the zipper to the cushion cover. Remove the pins. Slide the cushions inside the new covers and zip closed.
Wrap the back of the couch with upholstery fabric. Tuck the ends of the fabric under the couch and secure the fabric with staples from a staple gun. Pull the fabric down across the front of the couch, stretching it until it completely covers the back of the couch. Secure the fabric to the seat of the couch with fabric glue.
Stretch two pieces of fabric over the arms: one piece on each arm. Attach the fabric to the couch with glue and staples. Measure the front area of the couch, under the seat and add 1/2-inch to all sides. Cut a piece of fabric to this dimension. Tuck 1/2-inch under on all sides, creating smooth sides. Glue the piece to the front, covering any exposed seams.