How do you make a hole in a clipping mask?

I need to make a hole in a clipping mask. Here's an image of what needs to be done:

The image, outlined in red, has been created using a clipping mask, and the the white part between the ladys'(?) arm and the grass is what needs to be transparent.

Basically, the white parts are a part of the clipping mask, and I need to make them transparent. How do I do this?

Thanks!