Loosen the screw in the top bracket.
Hold the side of the door while moving the bracket back and forth along the track.
Stop moving the bracket when the door is level. It should sit aligned with the frame.
Tighten the screw.
Lift the bottom of the door up until the bottom pivot releases from the bracket.
Turn the pivot. Raise or lower the door until it's level.
Set the pivot into the bracket.
Spray the silicone lubricant spray evenly over the top track. Wait a few minutes for the spray to dry before closing the door.