1. Open a picture or save the one below.
2. Then create a new layer by clicking Layer >> New >> Layer...
3. Next click the bucket tool and change your color settings to black (#000000) like this 
4. Now fill that layer with the black using the bucket tool.
5. Then go to your layer settings (at the bottom right corner of the screen) and set Layer 3 to Saturation at Opacity 100% and your done ;D
Voila:
