Any time you wish to change the color of wooden furniture such as a dresser, you must strip the old color off. Finishes, paint and old stain residue must be removed. Do this with a liquid stripper for wood furniture easily found in hardware or home improvement stores. Lay an old sheet or drop cloth down in a well-ventilated area, and brush the stripper on with a large paintbrush. Let sit for a few hours, then return and scrape the goo off with a paint scraper. You may need to do this more than once.
Once all old finishes have been removed from the wood, allow the dresser to dry overnight. The next day, use fine sandpaper and gently sand the dresser. Sanding before staining serves two purposes. Sanding smooths any nicks or imperfections in the dresser. Also, sanding prepares the surface of the naked wood to take in the new stain.
Stain your prepared dresser any color you wish, but it is often easier to stain a lighter wood a dark color than a darker wood a light color. Choose your dark stain and brush onto the wood in the same direction as the grain. Most brands of stain should be applied twice, and allow to dry between applications.
After the stain has dried and you are satisfied with the look and color of your dresser, sand with very fine sandpaper one last time, clean off the sanding dust with a tack cloth, and apply one clear coat of wood sealer. This is to protect the dresser and make the beauty of the stain last longer.