Remove the hardware attaching the cabinet doors with a screwdriver. Remove the cabinet doors and uninstall any knobs or handles.
Sand the surface of the cabinet doors using a sheet or block of fine-grain sandpaper to remove any existing paint or stain. Sand with the grain of the wood in smooth, fluid strokes. This will ensure the surface of the wood is smooth and even.
Sand the surface of the cabinet doors with a sheet or block of coarse-grain sandpaper, if the wood has suffered a significant amount of wear and tear. You can easily sand out dents using a coarse block of sandpaper.
Use wood filler to fill in any cracks in the cabinet doors. Allow the wood filler to dry thoroughly before proceeding.
Stain or paint the surface of the cabinet doors. If using stain, apply in thin, even coats and wipe away any excess. Stain will darken as it dries, so a thin coat should be enough to achieve a medium-toned brown. If you want darker cabinets, apply another thin coat and wipe it away once the first coat has dried.
If painting, apply a thin coat across the front surface of each cabinet. Allow the paint to dry before inspecting if the finish is sufficiently opaque. If any of the original cabinet is showing through, or if the paint is uneven, apply another coat.
Paint or stain the backside of the cabinet doors, then the framing, so it matches the color of the cabinet doors.
Reinstall the cabinet doors within the frame using a screwdriver. Install the new handles or knobs.