First create your curve, example a simple nurbs circle. position the circle in front as close as you can get to the model. Select your circle, then select your nurb surface eg.. lighter.. then go to "edit nurbs, project curve on surface.
Once youve done that you can then use the "trim tool" to cut out around the nurbs curve..
Hope this is what you were wanting..
There's nothing normal about normals. In FACT i think the are abnormal.