How do I export a 2d sketch to a dxf file

I just spent 20 minutes searching this forum for an answer but couldn't find one.  I'm trying to simply get some 2d geometry from a 2d sketch inside an assembly to a vendor for some cnc waterjet cutting.  Am I missing something here?  I know there needs to be a simple answer that I am just not seeing.  Help.

SolidworksImport export