you wouldn't do it in Draw - you'd do it in Photopaint for starters. There's a number of ways to do it. To do it well will require some skill. You could use the Path tool and create a path around the guy, convert the path to a mask, then create a new object based upon the mask; you could do a rough mask around the guy, create a new object from this mask, apply a clipmask based upon the object's transparency and then paint on the clipmask with black to erase out the areas you don't need; or you could do Image|Cutout and follow the HELP instructions within the tool.