Hi JE,
Have you tried just replacing the graph with a new one from the palette? If you don't want to do this because you are using property nodes for your graph, you can do the following:
1) Put a new graph on the front panel
2) On your property nodes for the old graph, right-click and choose Link To->"your new graph"
Hope this helps,
Travis H.
LabVIEW R&D
National Instruments