Turn the chair upside down. Remove the seat and back from the frame with a screwdriver. Remove the old studs with a tack lifter or flat screwdriver. Tack lifters can be found at most hardware or home improvement stores. Using a straight tip screwdriver, remove staples from the fabric. Save the fabric to use as a pattern for the new cover.
Place the new fabric face down on a table or floor. Lay the old fabric face down on top of the new fabric. This is how you will get the shape of your chair. Pin the old fabric in place. Use scissors to cut around the old fabric pattern. Do this for both the seat and back pieces of fabric.
Remove and replace if necessary the foam underneath. Spray foam with a spray adhesive. Press the foam onto the chair's back and seat. Spray adhesive onto foam. Attach batting over foam. Trim away any excess batting. Let dry for 10 seconds.
Place the new fabric over the foam and batting on the chair's back. Pull the fabric taut and attach with the staples.
Cover the staples with the nailhead trim using a rubber mallet. Evenly space the nailhead tacks every 1/8 inch if you are using individual tacks.
Cover the back side of the seat back with new fabric. Turn under the edges about 1/8 inch all around. Affix the edges to the back with fabric glue.The seam can be covered with trim if necessary.
Reattach the seat and back to the chair with the original screws and a screwdriver.