I decided to take the dihedral out. Below pictures are self explanatory. The process took about 2 hours this evenng and its about ready to glue. I suppose that I'll pick up some expanding foam stuff to fill in the gap. The process started by shoving some wire on the bottom part of the tube/foam interface and working the tube so it came to the middle of the center root rib. Cut out a small portion of the center rib and then made a light ply piece for the center area to strengthen it.