State what you will do differently next time, to avoid repeating this type of transgression. 

By recognizing and acknowledging your faults and attempting to make amends to the injured party, you are taking the high road. This demonstrates your strength, courage, compassion, and wisdom.

... and the reasons it was wrong.

This is not to be confused with offering excuses for your actions. 

State your understanding of the reasons this was not the best choice and how ...

In order to show your sincerity when apologizing, you must be honest and vulnerable. That can lead to the cultivation of meaningful relationships. It can also lead to rejection, which is what makes it so scary. 

When you apologize, be willing to share openly and ca...

Take responsibility for your actions and admit your mistakes or transgressions. State them out loud. Yes, it will be scary. It will feel shameful for a time. But it is worth it.

... the other person toward forgiveness.

Now that your part is done, the only thing left to do is to sit back and wait. Work to release the guilt and let go of the desire to be forgiven...