I've hosted these images on Yahoo groups.
Unfortunately they do not allow links to their images.
If anyone is willing to host these, please let me know.
As for where to find the Edit Custom Properties option, in the Web admin GUI select:
Customize Views > Select a view to Customize (Node details or W.H.Y.) > Add resources > Node Details > Edit a Custom Property
I've created a new Custom View called CPE which has all the custom fields for any node available for updating. Then I link to this page directly from the Node Details page (as per my screenshots).