I did it in photoshop, but i think you can usually do it in your normal photo editor if you don't have photoshop. I moved the contrast bar to the right a little and then moved the brightness to the right a bit too (they're usually on the same control). Hue and saturation is usually on a different control, but i ignore the hue part and just moved the saturation to the right a bit. Saturation is just how coloured it is, so if you moved the bar all the way to the left it would make the image black and white, but moving it to the right makes it more coloured. Hope that makes sense!