I had a cockerel with a broken leg--about three months old.
I put the boy upside-down between my legs, pulled on the leg until it clicked straight, then cut up a yoghurt can until I had a 2.5x4 -inch square of plastic. I wrapped that around his leg, padded it with an old sock, secured it with electric tape, and left him to heal in a rabbit cage (with the bunny, they didn't bother each other) for a week before letting him run with the rest of the flock.
After that, I just kept an eye on him and removed it a month later. No complications, no trouble other than confinement and feeding him. He even drank out of the rabbit water bottle.
I hope yours is that easy to fix.
EDT: His leg did turn greenish for a while, but the color receded. I have no idea why it did that--It didn't look inflamed or infected otherwise.