Yet, how, in the short time span do you do that. This guy whined on about how he was wronged by the priest and this was a hurt from 30 years ago.
This amount of anger and hurt is not something that can be gotten through in the short time allotted. The important thing at this first meeting is to let him know that you care about him. Also, please remember that you will not be leading him to truth...it's the Spirit who will, if the man in question responds to the Spirit's bidding. Your main task is to show that this man is valued, accepted, and loved as a person.
Just because this person didn't immediately change his 30 year ways in one meeting, in front of you, does not mean that all hope is lost. The important thing is that you've shown that love can be found in the Church. Under the prompting of the Spirit, who will lead him and all of us into Truth, let us pray that the person starts to show up more regularly. When you see him, if he wants to talk to you, say a few words to him so he knows he's not alone.
When the fullness of time occurs, this man will open up to you, and it will be a rebirth. In the meantime, don't be too hard on yourself by blaming yourself for allegedly not being able to get this man to completely erase from his memory 30 years of anger. You don't know what the Spirit can do with small openings like this one--and trust in Him.