1. To edit the base of the model, click on the Edit Curves tab. It may be convenient to view from the front view. Within the Edit Curves tab, make sure the Select option is chosen. Using the mouse, make a rectangle around the portion you wish to remove. Also observe the isometric view to ensure that the entire base is selected.

2. Click on the Delete button at the top of the Edit Curves tab.

3. You now need to re-zero the model since it is floating above (0,0,0). Click on the Advanced... button within this tab.

Select Part to Origin and click OK.