Scrape off loose paint with a stiff wire brush, spatula or putty knife.
Strip existing paint off the barstool with sandpaper while wearing a dust mask and eye protection. Wrap sheets of sandpaper around the legs and other small round sections and rub away the paint. Fold the sandpaper in half to reach into crevices.
Wipe the barstool down with a tack cloth to remove dust from the sanding process.
Apply a chemical paint stripper to remove stubborn paint remnants while wearing gloves rated to protect your hands from corrosive chemicals.
Fill small holes and dents with wood filler. Dry and sand smooth the filler according to manufacturer's specifications.
Apply a layer of primer to the chair with a small paintbrush. Allow to dry. Sand the primer with a fine-grit sandpaper.
Paint the stool with a semi-gloss paint in the color of your choice. Sand with a fine-grit sandpaper and apply a second coat of paint.
Seal the paint with a polyurethane sealer. Apply additional coats of polyurethane to match your desired level of sheen.