Question: 
Say I become angry unadvisedly or desire to revenge wrongs done to me. How may I remedy this sin?

Answer:
Against unjust anger or a private desire for revenge, meditate on the following:

1. Consider that injuries happen to us by the Lord's appointment for our good (2 Samuel 16:10).

2. Reflect on God's great goodness in forgiving us far more sins than we could ever forgive in others.

3. Remember that Christian love dictates that we forgive others.

4. Realize that we must not desire to destroy those whom Christ has redeemed by His precious blood.

5. Understand that we ourselves are in danger of God's wrath if we allow our anger to burn against our brother. As Jesus said, "Forgive, and you will be forgiven."

6. Recognize that we do not know all the circumstances of the facts, including the intentions and purposes of those against whom we are angry.

External remedies or methods to bridle anger include:

1. Imitating the Lord's clemency, who often tolerates the wicked for a significant period. "Learn from me, for I am humble and meek."

2. Introducing a pause or delay between feeling anger and acting upon it. Athenodorus advised Augustus to recite all the letters of the alphabet or A, B, C before speaking or doing anything in anger.

3. Avoiding places where those who provoke our anger are present.

4. Refraining from engaging in contention, both in words and actions. "Do nothing through contention."

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Source: Satan's Sophistry Answered by Our Saviour Christ by William Perkins