Anyone who works with him should remember, 'Aspie see, Aspie do." Be sure to get things right the first time, if working with them on social skills.
I would recommend just presenting oneself to the pastor and say “Here I am.” Start with parish volunteering. He should also make inventory of what he can or can’t do. The Myers-Briggs might be helpful, as well.
One of my main points is not to go overboard on correction. An explanation of why such is not done, and why we do it another way usually suffices. Doing something needed numerous times over until the person understands is helpful, as well. I personally never learn anything – well, rarely – the first time, since I have a processing delay. This is especially important when teaching anything mechanical that requires precision.