If the door is level, consider shaving it. Of course, this would mean it has to be removed which is done by either removing at LEAST one part of the jam moulding, or by not doing this and simply lifting it off the track.
If the door isn't level, then it need to be removed and the tracking needs to be leveled. (You may need to 'shave' the top of the door if it would 'rub' after you raise the track.
You could have a new door installed if all else fails.
The trick is removing the jam-moulding (1 or both mouldings). Then, level the tracking. YOu may need some wood putty to fill the 'old holes' before you drill new ones. Or, you can 'plug' them with wood dowels. It's going to take a little doing but it will be more time consuming than hard.
My best to ya and hope this helps.
PS: For ease of working, it would be nice if your door could be simply 'lifted' off the track and removed. But, I think it's unlikely unless it's a relatively newer door.