How to Change the Stain Color on Wood
Sand down the wood using a fine-grain sandpaper or a palm sander with fine sandpaper. Ensure that you remove all of the previous stain over the entire area of the wood.
Brush off the surface of the wood using a nylon bristle brush or compressed air blower. Ensure that you remove all sawdust from the surface of the wood.
Apply your desired color of stain to the wood per the manufacturer's instructions. Stain mixtures come with instructions on the can or bottle.
Let the first coat of stain dry thoroughly, usually for 12 to 24 hours, then add a second coat for a rich and complete stain coating. Be sure to apply the coat evenly to reduce the appearance of blemishes in the stain.
Coat the surface of the wood again with a polyurethane coating or sealant to produce a shine to the stained wood. This is optional, however it will increase the luster and give longer life to the stained wood.