Even though I've never had a rooster, I've learned about them from my grandparents.
One of my tips for toning down the behavior of an aggressive rooster is to separate him from the flock for a day or two. This will force him to chill out since he won't have the authority to boss the other chickens around, nor you since he will be confined and isolated. Sometimes roosters get so caught up in themselves that they need to be put in "time out" for a little while as they learn their place again.
Add him back to the flock and make sure you observe the chickens' behaviors to make sure nothing goes wrong. Hopefully, through the separation process, it will have caused him to relax a little and not be as aggressive.