Not real sure where the original drip rail was or what it's configuration was, Randy.....from this picture it appears that they either pounded the upper edge of the OEM rail in, or cut the old one off and added this one---kind of a triangle shape or????

As for taking the old one's off, are they formed from the side and roof portion meeting together in a flange, or are the OEM rails just an L shape tack welded to the outer skin????