Turn the bar stool over so the seat is resting on the floor. Pull out the staples or nails holding the fabric in place by prying them with a screwdriver. Use a hammer to tap the screwdriver and wedge it under the staples, if needed.
Lay the fabric removed from the seat on top of a piece of newspaper and trace around it to create a pattern.
Check the foam cushion or pad to verify if you can reuse it with the new cover. Trace the cushion shape on a piece of newspaper, if you need to cut a new piece for the bar stool.
Use the newspaper pattern to cut out a new piece of decorator fabric for the covering. Cut out a piece of chair foam or padding, if needed. Alternatively, use three to four pieces of thick polyester batting to replace the seat cushion. Attach the cushion to the bar stool with white glue to hold it in place while attaching the fabric cover.
Lay the fabric on a flat surface with the right side facing down. Set the bar stool seat in the center of the fabric, so the stool legs are facing upward.
Pull the fabric on one edge to the underside of the chair and secure with a staple. Repeat this with the fabric edge on the opposite side. Turn the stool over to verify the fabric has no puckers and lays flat. Continue to secure the fabric underneath the stool and secure with a staple, securing first one side and then its opposite until all the fabric is secure.