Can someone fark this pic of Gurley and Thor for today's weather delay?

Others may have different suggestions, but for turning white skin black, it's kind of a "hit and miss process" depending upon the source pic.

1. Take the selection tool and highlight area in question

2. Either use a color balance tool to vary shades over and over, and/or then mess with light balance to darken.

Sometimes, depending upon the blackness, can adjust color saturation and remove a lot of the light skin.

Sometimes, can use the cloning tool to either brush the new area with the black or do a light fill.