help nailing up mezuzah

Question

in my orthodox shul there is a gentile who is preparing to convert under the auspicies of the rav, and is quite observant of shabbat or kashrut=he is not an oveid avodah zarah but not a Jew. he has seen me struggling tryting to nail in the mezuzah on my new apt door, he is much better at this and has offered to help me(i was going to use tape in the end). can he or can he partially and i can do the finishing touches or blows with hammer. or not? thank you