490064 Photoshop expert - remove background + color

Hi guys, I am looking for a professional photoshop guru who can remove the background to 1 photograph (preferably transparent) leaving just the team members in the picture. Additionally I need color alteration to every one's jeans (pants/trousers) to change to the color black so they look more like uniform. Attached is a sample of the picture. The original will be sent to the winning bidder which is 300dpi 4228px x 1680 Thanks!