Sometimes humming to yourself can help. Other times it helps to think of the person as an animal that kicks. You don’t get angry at it, you learn what not to do in its presence.
On the path of WIY, you can change aspects of your personality by changing your handwriting. You can curve your letters more and round off the bottoms of g,q.
It takes a long time to change your thought process. But by constantly telling yourself that it doesn’t make sense to be upset, with the logic supplied by the previous posts, eventually you will notice that your reaction will change.
I once heard that when the Chofetz Chaim felt that he was getting upset, he would speak very quietly. This puts you in low energy mode, and thereby dissipates the anger.
One more thing, so far, is to mentally put the problem into words. Once it is an intellectual issue it is no more an emotional one. You tell yourself, this person is doing something terrible by doing this, and it is not right because of that. The more detail you quantify and put to words, the better off you are. This, by the way, works for anxiety, too. Put your problems into very specific words.