Losing weight from my backside?

Now that's it's summer, I have a lot of time to go to the gym now. I'm a size 6 but I'd love to go down to a size 2 by the end of the summer. I have a small upper half of my body but my lower half is seriously disgusting. I have a wide and big hips which I absolutely hate. How can I get rid of the weight from my lower half? Which machines should I go on in the gym and what other exercises can I do?