Remove the spline from the old cane on the chair. Break the bond on the spline and the chair by carefully cutting each side of the spline with your utility knife. Remove the spline by prying it away from the chair with your awl.
Remove the cane seating. Scrape excess glue or residue away from the groove in the chair with your utility knife.
Place your new pre-woven cane material in water and soak it until it softens. Lay the softened new pre-woven cane material over the opening in your chair glossy side up. Align the pattern on the pre-woven material parallel to either the front or back edge of the chair. The edge you pick does not matter.
Tap a wooden wedge with your mallet into the center of the back rail grove on your chair. Lightly stretch the cane toward the front rail on the chair with your hands, and wedge it at the center of the rail. Repeat for all four sides of the chair seat.
Tap the pre-woven cane into the groves with your mallet and wedge with a blunt tip. Place the wedge into the grove and tap it with the mallet. Tap the cane into the grove alternating from side-to-side and front-to-back to prevent it from distorting.
Remove the wooden wedges from the chair. Cut off the protruding cane around the grove with your chisel.
Measure a piece of dry spline against the grove on side of the chair and mark the ends of the spline with your pencil. Repeat for each side. Cut the ends of the spline at a 45-degree angle with your chisel. If your seat is rounded, use one piece of spline.
Place carpenter's glue into the groves on the chair. Gently press the spline pieces in place. Tap the spline with your mallet and wooden wedge unit it's flush with the surface of the frame on your chair. Allow the carpenter's glue to dry, approximately 24 hours before continuing onto the next step.
Seal both sides of seat (top and bottom) with lacquer and your paintbrush. Allow to dry thoroughly according to the manufacturer's directions before using the chair.