What breed and how old are your roosters? If they're juveniles, you have a big yard, and they don't have spurs, they should just knock each other around until they figure it out. Currently, I have three bantam crosses that are being absolute idiots and the silver one looks awful because there's blood all down his throat--but it's coming from one tiny nick on his wattle. He's fine, and would far rather be loose than confined to the old rabbit hutch.
If you have large game roosters, older roosters, or roosters that just won't stop fighting, definitely follow EggSighted's recommendation and consider investing in a few Igloo doghouses. Tethering roosters is the easiest way to 'free range' them, and you don't have to worry about them bothering the hens. (Also, if arranged right, it looks kind of cool.)
Better, with a tethering system and the hens free-ranging, they sometimes choose what rooster they prefer, which helps me with rooster selection.
EDT: Tethering roosters--they'll take a while to figure out the foot thing, sometimes up to a day. I just use some braided parachute cord to make a cuff, tie it around the foot, make sure the loop has a little bit of give (it's not supposed to be snug; it should move around the foot easily.) I use a small bolt-snap (mine came off of an old purse) tie some cord to it and tether the other end to a ring, which goes around a stake.
I use an Igloo doghouse; the stake should not be next to the Igloo or the chicken will just walk around the doghouse and then stretch towards wherever he wants to be while looking pathetic. If you just tie the cord to the stake instead of the ring, the chicken will wrap the cord around the stake.
I use the hillbilly/redneck method of closing the doghouse at night too. You might want to invest in some actual doors; I use a piece of plywood and a cinder block, which double as a sun-porch during the day.
Make sure to put the doghouse in some shade if it's going to get hot.
