How can i get my legs skinner?

I see alot of girls today that have a huge gap in between their legs, i want that. im not fatt or anything, its just the top of my legs are fatt, well most of it. the side is all muscle, how can i get my legs very thin, so i have a gap in between? and i really need to know how, because im starting to model, for target, khols, and abercrombie and fitch. so pleasee helpp!