Controling one's anger involves engaging in a large amount of self control. If you are able to stop and control yourself when you know you are getting angry it can be very helpful. You might take a few deep breaths, walk away from the situation, or count to ten in your head.
If you are not able to do these techniques on your own you can try things like meditation to help you find a centered balance in life. You may also seek a doctor's help with medication or a therapist's help with therapy sessions that help you get to the root of your problems and employ techniques to find self control.