My plan was to take apart the ends, and raise the lower rail up high enough that a 4 foot dowel could reach the center of the top curved piece (all the other dowels would be shorter than the 2 center ones on either end.)

The back side would be the same idea, taking apart the safety rail and replacing all the dowels in it to make it the correct height. The front side would require more thought though since it was made 18" too short in order to accomodate a ladder (not shown.)