I'm new to Houdini and have an assignment that allows only the use of NURBs. I have an existing NURBs surface which has been previously skinned and points have since been edited using the resulting surface. I'm wondering if there's a way to extract my edited curves from this surface so as to skin them with a new curve (see picture)? So far I've tried converting the object and using carve to extract the curves without much luck- I'm a bit stumped. Any help would be appreciated, thanks!

for extracting curve form surface,you can try couple of steps like this:
group the nurbs hull you want as "edge";
use "lab edge group to curve" to extract the curve(polygon);
then convert the curve to nurbs

julia923
and using carve to extract the curves without much luck

you should be able to use Carve SOP in Extract mode to extract NURBS curve(s) out of NURBS surface in U or V direction, what exactly was the issue you were running into?