If they're fighting, I agree with using water. They aren't going to like the water and it will scare the heck out of them which they don't care for either. Or go to your window and start making noises back at them. Get a trap and lure them in with some food and take them to your local shelter (if you have the time or energy to do that) I have used bleach soaked paper towels in the past as well. I would soak them before bed and set them near the area where I hear them. Good luck to you!
Go to your local pet supply and buy Feliway. It's a spray that most cats hate when they come to it. Just spray the area that they like to hang out on and rest. When they come to it and smell the spot, they should bounce.