Spread out newspapers around the cabinet area. Disassemble the cabinets, removing all hinges, knobs and other hardware. Lay out all the doors and other pieces.
Set up the vibrating sander with its heavy sandpaper. Sand the surface of each piece, taking off all the existing finish and digging into the top layer of the wood.
Repeat the sanding process twice more, using medium sandpaper and then fine sandpaper, to get all the old finish off, leaving the surface open and clear.
Apply wood stain over one section of the cabinet with your finishing brush, laying it on heavily. Let the stain sit for about a minute, then wipe off the access with old rags.
Repeat the staining process for each section of the cabinet. Let the stain set 24 hours.
Coat the whole cabinet with a polyurethane gloss, spraying it on in thin layer. Let it dry four to five hours, lightly buff with fine sandpaper, wipe off the dust, and spray it again. Repeat, adding at least three layers and up to five, according to the look you want.
Put the cabinet back together.