I bought my Traverse under the PEP 2 pricing for new vehicles program (which GM had for a few weeks in March). The plan didn't allow me to delete options, otherwise, I would have deleted the cross rails that came with my "tagged" Traverse. The wind noise was intolerable (I didn't know/think to look to see which edge was forward). Not to mention that the cross rails WILL reduce your fuel economy (by as much as 10% by some estimates) - which was/is reason enough for me. I removed mine. Removal was pretty simple.
Each end of the cross rail has a plastic cover held on with one screw. Under that, the rail is held in place with two screws (all screws require a star bit - my dealer supplied me with a wrench). Once both cross rails are removed, the sliders can be removed. Start by removing the small rubber stopper in the middle of the side rail, slide each of the sliders to the middle and lift out. I left the small rubber piece out and am storing it with the rest of the pieces.