Pull the drawer open and push to close. Note any gaps between the drawer front and the drawers adjacent to it. For example, if there is a gap on the bottom edge of the drawer, the face plate needs to be lowered slightly.
Measure the gap with a tape measure.
Pull out and remove the drawer.
Loosen the two screws on the inside of the drawer face plate where it attaches to the drawer sides.
Slide the face plate to the correct position, based on your measurements in step 2.
Tighten the face screws and reinstall the drawer.