Restaining kitchen cabinets involves more steps than simply repainting them. Before you can begin staining them the color you want, you must first remove all the old finish, which isn't the easiest task in the world. But if your cabinets look the way you want them to when you're finished, then it's well-worth all your effort.
Remove all the hardware on the kitchen cabinets and set aside all pieces in a safe place so they don't get lost.
Turn on the exhaust fan or open the windows, and apply the stain stripper. Formby's Furniture Refinisher is one of the best brands and should work well on most cabinet finishes. If the cabinets are coated with layers of polyurethane, you should use Formby's Paint and Poly Remover.
Apply the remover to the cabinets going with the grain of the wood. Formby's recommends using a clean steel wool pad (not the soap-filled kind) with the refinisher and applying it with the grain of the wood. If there is carving on your cabinets, some refinisher or remover can be applied with an old toothbrush to get into the nooks and crannies. The refinisher does not need to sit on the wood at all - just apply and wipe off. If you use the paint and poly remover, let it sit for about 15 to 20 minutes.
Wipe off the Formby's refinisher with rags. The paint and poly remover should be lifted off with a plastic scraper. If there is remaining residue, lightly sand (with fine grain sandpaper) the remaining residue off and gently wipe the wood with steel wool with the grain of the wood, if necessary. Rinse the wood with just a little bit of water and wipe it off immediately before it has a chance to soak into the wood. This should remove even the darkest of stains and allow you to refinish in a lighter color.
Apply the new lighter finish and allow to dry completely in a well-ventilated room.
Apply the protective finish to the cabinets, allow it to dry completely, and reattach the hardware.