Open the cabinet door. The hinges should have a cover plate. Use a flat head screwdriver to pry off the cover plate.
Look for the long arm portion of the hinge attached to the cabinet door. The screw closest to the hinge typically moves the door back and forth. The screw closest to the door usually moves the door from side to side. To move the door up or down, you will need to loosen the mounting plate on the door, move the door then tighten the plate.
Start by adjusting the lower set of hinges. This will prevent you from accidentally detaching the door while balancing it. Adjust one door of the cabinet first then adjust the second cabinet door. If you adjust one crooked door with a second crooked door, you will have to start over. The doors should align with the cabinet's straight opening.
Finish the balancing process by replacing the covers over the hinges. Press the covers to snap them back into place.