1. Know exactly how you feel about what happened and be able to articulate what about the situation is not OK. Then, tell a trusted couple of people about your experience.
2. Make a commitment to yourself to do what you have to do to feel better. Forgiveness is for you and not for anyone else.
3. Forgiveness does not necessarily mean reconciliation with the person that hurt you, or condoning of their action. What you are after is to find peace. Forgiveness can be defined as the “peace and understanding that come from blaming that which has hurt you less, taking the life experience less personally, and changing your grievance story.”
4. Get the right perspective on what is happening. Recognize that your primary distress is coming from the hurt feelings, thoughts and physical upset you are suffering now, not what offended you or hurt you two minutes – or ten years – ago. Forgiveness helps to heal those hurt feelings.
5. At the moment you feel upset practice a simple stress management technique to soothe your body’s flight or fight response.
6. Give up expecting things from other people, or your life, that they do not choose to give you. Recognize the “unenforceable rules” you have for your health or how you or other people must behave. Remind yourself that you can hope for health, love, peace and prosperity and work hard to get them.
7. Put your energy into looking for another way to get your positive goals met than through the experience that has hurt you. Instead of mentally replaying your hurt seek out new ways to get what you want.
8. Remember that a life well lived is your best revenge. Instead of focusing on your wounded feelings, and thereby giving the person who caused you pain power over you, learn to look for the love, beauty and kindness around you. Forgiveness is about personal power.
9. Amend your grievance story to remind you of the heroic choice to forgive.

These 9 steps are from http://learningtoforgive.com