How can I delete a path in sketcher assigned to a path dimension?

Hi

I have a sketch that I need to control the path length.  The path dimension holds promise for me, and in trying to learn it, I created a path that is not complete.  So, I deleted the dimension and tried to recreate it selecting all of the desired entities.  I get this message:

Where can I find reference to the "existing path" and how can I delete it / modify it?  In my case today, I will simply delete the sketch and recreate it, but I am confused about what a path is and where else it might be used and how does one know that it exists and can it be modified... etc...

I am really just trying to control the total length of multiple sketch entities - like a perimeter dimension.  Am I using the correct tool?

Thanks!

-Nate

SolidworksParts And Features