I'm a recreational fitness user. I'm 27, 5'11" tall and weigh 173 lbs. I'm probably around 15-17% body fat now. I'd like to cut it down to about 10%, although I'm a bit unsure of what that would look like. To give a better idea, I'd like to be looking like the guy on the left in the picture below. I think I'm pretty close to the guy on the right now, although I probably have slightly more body fat.
For such a goal, do I have to go through a whole bulk/cut deal and all that serious stuff? If not, how do I make sure to gain the muscles and lose the fat to transition from the right pic to the left pic? I know this is a very broad question, but I'm just looking for the big picture - I'll figure out the details later.