Stage 1, Thought. Take a long, slow, deep breath and while you are doing that visualise these words scrolling across a screen in front of your mind's eye:
Thank you XYZ* for helping me understand that there is no requirement for me to feel anger, and that if I wish I can extinguish my anger. I reach deep into myself. I gently and lovingly take hold of my red, boiling ball of anger, bitterness, resentment, frustration...
Visualise the hot, red, glowing ball of anger deep inside yourself. Inside the ball is your angry self, your mouth wide open, shouting, screaming in rage, fists beating furiously against the inside of the ball. Visualise your hands gently taking hold of the ball. Now start exhaling, long and slow, while you continue visualising the words and the images described by the words.)
I cast it out of myself, it withers and dies without me to sustain it. And now I have no anger. I am in peace. I have no need of anger. Thank you XYZ*.
By now you should have completed your long, slow exhalation. Continue to the next stage.
Stage 2, Affirmation, is identical to Stage 1 except that as well as visualising the words, say them out loud. The breathing pattern in Stage 2 is the same as in Stage 1.
Stage 3, Deed, is the most difficult of the three to perform. Stage 3 is identical to stages 1 and 2 except that as well as visualising and/or affirming the words, enact the words, be the words. Be in peace. Be in a state of no anger. Do peace. If you feel you can't, fake it until you make it!
*For XYZ substitute the name of anyone or anything you admire and respect. You can but you don't have to use the image, concept, word or name of your favourite god here. You can use your own name. If your name is "Jon" then you could say, "Thank you Jon". Alternatively, you could thank your mother, your father, the heavens, reality, whatever. It doesn't matter who you thank as long as you choose something or someone you admire and think well of.