An attack rooster is just a little confused about the pecking order. Resetting the pecking order is not difficult; just put your game face on.
Enter the chicken yard and immediately go on the attack before he can: chase him hard, round and round. If he tries to chase you have a broom in hand to knock him around until he's convinced to run.
Once he's convinced to run hard away from you, then catch him. Hold him upside down by the legs and shake him a bit. When roosters fight they bite the comb. So grab the comb, pinch it a bit, and shake his head around with it. Toss him to the ground and keep chasing him until you're satisfied there's no fight left in him.
Next involve the kids. Let them pinch the comb and hold him upside down, toss him and chase. That should do the trick.