Teri, the rollers are located inside the bottom frame of the door. You must remove the door. To do this grasp the door, left & right side and lift up you will then swing the bottom out. There is a channel in the bottom, this is where the rollers are located. You should find a screw on either side of the door. These are removed and the rollers should come out. I have found that it is easier to do this one at a time. After you have replaced the rollers and the door is reinstalled there is a screw that adjusts the tension on the rollers. Hope this helps you out.
Jim Burton, July 2006