Stains should be removed using steel woolen pad along with lemon oil. The pad should be dipped in lemon oil and rubbed in the same direction as the grain. Dark rings should be removed using a mixture of warm water and oxalic acid. The surface should be sanded and the solution should be applied. The solution should be left in place till the stain goes away. The surface should be buffed using steel wool pads allowing it to dry completely.
The wood restorative oil should be applied on the surface. The oil should be worked in the wood completely working in small areas and going back over the surface. The entire surface should be covered using the oil and allowed to sit for few hours.
The excess oil should be removed and the surface should be buffed. A wax or polish should be applied sparingly using a soft cloth.