Edit Actors
The Actor definition can be modified as you want.

How can I do it?
There are two ways to edit an Actor: by using the Edit button on the Actor toolbar or pressing the Edit command on Actor menu.

Editing Actor
Like as show in the picture below, You need to define cardianl point to edit or define an actor:

In order to optain the best result, is important to place cardinal points on correct coords.

Move points
It is necessary to have the button activated to be able to move cardinal points. To move a cardianl point you must:

1)Move the mouse pointer near the point
2)Hold down the left mouse button
3)Move the point where you want
4)Release mouse button

In order to move cardinal points on correct coords, you can refer to the Point Helper panel: look where are the point you are moving and place in the same zone.

The point you are moving will be yellow.

The results are shown step by step in the Preview Panel:

Move cardinal points until you can see acceptable preview.