A stool is subject to a lot of wear and tear over the years, resulting in a cushion that may not look its best even if the rest of the stool is structurally sound. Rather than replacing a stool just because its fabric is worn or no longer fits in with the home's decor, reupholster it to give it a fresh new look more suited to your tastes. Upholstery fabric is required for a stool, as this thicker material is designed for durability, compared to decorative, thin fabrics such as linen.
Flip the stool over or onto its side on a work table to access the area under the cushion. Remove the staples using a staple remover or a flat-head screwdriver.
Smooth the old fabric out while pulling it way from the stool structure. Remove the foam, if any, keeping it as intact as possible. Set the stool aside.
Place a new piece of upholstery fabric face down next to the old. Slide the old piece atop the new to use as a template. Trace around it with a pencil, then cut the fabric out along the lines using scissors. Discard the old fabric. Cut a piece of batting to the same size as the new fabric and spread it out atop the fabric.
Set a new piece of upholstery foam next to the old, if the stool had foam in it; otherwise, skip this step. Set the old foam atop the new and trace around it with a marker. Set the old foam aside. Slice through the new foam along the marker lines using a utility knife, pressing down on the foam if it is thick. Use scissors to complete the job if you can't cut all the way through with a knife.
Set the barstool upright. Apply spray adhesive to the stool surface where the foam belongs. If the stool does not have upholstery foam, skip this step. Press the new upholstery foam in place, allowing the adhesive to dry for several hours or as recommended in the manufacturer's instructions.
Flip the stool and cushion combination on to the new upholstery fabric, which is still upside down with the batting on top.
Wrap the edges of the fabric up over the stool and onto the underside of the seat. Press down on the stool while working to help keep the fabric taut. Staple opposite edges first, then about every inch or two around the edge. If the stool is somewhat square or rectangular, fold and tuck fabric corners as if wrapping a gift. Continue stapling until all fabric is secure. Trim bits of excess fabric away, if necessary.