Subtracting the Ellipse from the Horn
The ellipse is subtracted from the horn to create a hole.
 In the model tree, select Ellipse1.

Subtract using one of the following workflows:
 On the Construct tab, in the Modify group, click the Subtract From icon.
 On the model tree, a rightclick context menu is available on the primitive. From the list select Apply > Subtract From.

In the model tree, select
Union1.
Note: The T in the model tree indicates the target (object that was subtracted from).
 Click Create to subtract the ellipse and to close the dialog.