Cut the seat off the legs of the rocking chair with a circular saw. Make the cut so that it is flush with the lowest point of the chair’s skirt. The skirt consists of the pieces of wood along the front, back and sides of the chair below the seat. Sand the cut area with medium-grit sandpaper to remove any splinters.
Turn the chair upside down, so you can see the bottom of the seat. Either set it so the back hangs off the side of a table or place the back on the work surface so the seat is at an angle, depending on your available work surface.
Place a flat swivel on the underside of the seat. A swivel consists of two pieces of metal that have circular interconnecting parts that allow the metal pieces to rotate independently while remaining attached. Center the swivel on the seat and secure it in place using the screws that come with the swivel. Screw the screws into the wood of the rocking chair seat.
Attach the other side of the swivel to a chair base. Place the swivel in place, centering it on the base. Turn the seat so you can reach the holes and screw the screws into the base. Use any style base you want, such as a standard chair, a base on casters or a barstool.