Keep the area clean and mositurized as some break-outs occur when there's not enough moisture so it produces too much oil to keep it stable. Drink water, exercise, and apply aloe vera to it every night before you go to bed. You can find it in your local health food store. The kind in the bottle is find but straight from the plant is better. Just cut the tip of the leaves off and use the juice.
What I would do is shave any hair that you may have on those areas (because hair is a cause of acne) then take regular showers, and scrub those areas. I've had this problem, and lots of hard scrubbing and showering helped a lot.