Spread wood glue along the broken or cracked portions of a wooden keyboard tray. Clamp the pieces together. Keep the clamps on the tray until the glue dries, usually between 24 and 36 hours.
Line up the replacement metal bracket on the side of the keyboard tray. The wheel should face outward. Insert the screws into the holds and screw them into place.
Grip the bent metal with a pair of pliers. Slowly straighten out the metal.
Tilt the keyboard tray downward as you slide the wheels into the bars on the desk. Level the tray and put it in the rest of the way.