many tools
First
Open your image, and double click on the "background" name in your layers pallette. This will turn it into a layer.
Second
Open the extract tool: Image>Extract or Option/Alt+Cmd/Ctrl+X
Third
1. Take the marker tool and trace around the image you want to extract. Keep the marker 1/2 way on the image and 1/2 on the background. For solid areas use a small brush, for softer areas like the loose hair, use a larger brush. Tip: to adjust the brush size use the [ and ] keys.
2. Now take the bucket tool and fill the area you want to keep.Click OK.
Thanks!