Slide the panel open slightly, and stand between the two panels. Grip the front edge of the panel with one hand and the rear edge of the panel with your other hand.
Lift up on the door and swing the bottom pivot out of the bracket on the floor. Lower the door to remove the top roller from the track, and the top pivot from the top bracket. Carefully lay the door on the floor.
Grip the bottom pivot with your hand and pull it out of the door. Twist the pivot counterclockwise to extract it if it is threaded into the door. If you are also removing the plastic sleeve that the pivot sits in, pull it out with needle-nose pliers.