Program: Photoshop CS
Translatable: HELL YES, all you need is a hue/saturation layer
Difficulty: RIDICULOUSLY EASY, SERIOUSLY. SERIOUSLY.
1. Open your picture. I'm using William Beckett
2. Layer >> New Adjustment Layer >> Hue/Saturation.
And your saturation is...
For this one, because the picture was so big, I duplicated the hue/sat layer.
SEE, HOW EASY IS THAT.
here, here, and here.