How can you forgive someone without the other person there if you are the type that requires confronting the other person in order to let go?

Forgiving a person can be hard depending on the events that has taken place. Just remember that you are forgiving to give yourself closure and it does not mean the relations will be mended immediately. If you require the other person to be physically present also, then that means you need to communicate more with him or her on the issue that offended or hurt you. If this is impossible then your only option seems to be to come to terms with what has happened or try to forget it.