Place the new fabric face up over the cushion, centering the pattern, if any. Place additional batting (padding) beneath the new fabric if necessary.
Trim the extra fabric away leaving a 1-inch overlap around the edge of the existing cushion.
Use the staple gun to secure the new fabric at the edges of the cushion where it meets the frame and use the scissors to trim off the extra 1- inch of of new fabric.
Select a braided upholstery gimp in an appropriate style and color, cut to the proper length. Use the gimp to cover the staples at the edge of the cushion. Secure with fabric glue. Trim off the end, ensuring it is glued securely in place.