muddasick:
You can open the library part (select the part and go to File>GDL Objects>Open Object...). From the main Library Part window click on the 2D Symbol button and a window with the 2D symbol will open and the Toolbar will appear, with most the 2D drawing tools active. You can now add a Hotspot as you would in the main ArchiCAD 2D window. Save the part, and the new Hotspot should appear with the other Hotspots on the part. You can also use the other drawing tools to modify the 2D symbol if you wish, but if you make the overall size larger or smaller then the 2D might not match the 3D.
Hope this helps.
David