Disassemble the table. Remove the rails, which are often bolted on from the underside. Unbolt and remove the pockets. Pull out the staples (if any) for the cloth and peel it off the slate bed, then remove the screws attaching the slate. Disconnect the legs by removing their bolts or screws.
Inspect the condition of the table's base and apron and decide if and how you want to refinish it. There are multiple ways you can do this; sand the surface and apply a fresh coat of stain or varnish, or glue veneer sheets to the sides for a new look.
Refinish or replace the legs. Apply the same style of refinishing that you used for the base and apron. If you want or need to replace the legs, replace all four together and get a set that can properly support the size and weight of your table.
Replace or restore the rails. Peel the billiard cloth off and carefully pry off the cushions with a putty knife. Clean off the dried glue with adhesive remover, use contact cement to glue the new cushions to the rails and trim the rubber along the edges with a utility knife.
Replace the slate bed if it is cracked or damaged. Purchase a slate bed that's the correct size for your table. A 9-foot table requires a bed that's 100 by 50 yards; most home tables are smaller. Screw the bed to the table after reattaching the legs.
Cover the table with new billiard cloth; 21 to 24 oz. is usually needed. Cut strips of cloth to glue to the rubber cushions on the rails. Apply an adhesive spray to the slate, stretch the fabric across the table as tight as it can go and staple it to the table near the edge. Trim the cloth where the pocket holes are and staple the cloth to the inside of the holes.
Reconnect the rails, pockets and any other pieces to reassemble the table.