Can you post a picture of the corner? You can "very" carefully remove stitches. Realign and re-stitch. Again, "very" carefully.
Determine where/what the problem is first though. Is the binding placed too far out of the quilt edge? Did the seam line get too big at that edge?
Pay attention to the direction of the folds so you can repeat them when you re-stitch.
You can do this!