Gloss is desirable on cabinets, but if you're planning on painting or re-coating the cabinets, the existing gloss finish can keep the new coating from adhering to the cabinets. You have a couple of options for removing the gloss, and while they aren't difficult, both are time consuming. Set aside a weekend, and roll up your sleeves.
Sand off the Gloss
Remove the cabinet doors and drawers from the cabinet base. Use a screwdriver to remove the hinges and drawer pulls.
Fold a sheet of fine-grit sanding paper into a square and sand over the entire surface of the cabinets, the cabinet doors and the drawer fronts.
Sand lightly. You're not trying to smooth the wood grain, only the surface gloss.
Use a fine-grit foam sanding block for the flat areas on the cabinet base and on the backs of the cabinet doors.
De-gloss With Liquid
Disassemble the cabinets as you would if you were sanding them. In order to apply the liquid evenly, you must have access to all parts of the wood.
Wear chemical-resistant gloves and splash proof goggles, and read the manufacturer's directions and safety precautions.
Pour liquid de-glosser onto a clean rag and wipe the rag over the glossy surface of the cabinets, doors and drawer fronts, rubbing with the cloth until the gloss is gone.
Wipe off excess de-glossing liquid and let the cabinets dry completely before re-coating.