How can I scale a subsection of a mesh created with the screw modifier? I've created a mesh that somewhat resembles a phone cord by following this tutorial.  Now I want to modify a subsection of the structure.  Specifically, I would like to scale down the "diameter" of the structure somewhere in the middle.  

Is there any way to do this besides creating separate meshes for each of the differently-sized subsections?
If you are trying to adjust the Curve path in this case, you can follow this way:


Tab into the Edit Mode, select one or more points on the curve;
Then press AltS to loosen or narrow it as you want (or click Scale Feather button in the Toolshelf).