In Photoshop, I opened the image up and first chose Image -> Adjustments -> Replace Color. I shift-clicked (sampled) each color of source code by clicking on a few different pixel of the text. I dragged the Lightness slider to zero to make the source code black thereby "erasing" the source from the window.

Next, I opened up Image -> Adjustments -> Levels and dragged the grey (middle) adjustment slider toward the left to lighten the darker areas. Dragging the white (right) slider a little left also helps to reduce the maximum blackness of the image.