It also depends on your scenario.
Unless there are obvious signs of diabolical possession, it's very unlikely that a priest would do a solemn exorcism.
Any valid priest can pray some of the more general exorcism prayers, and there are also various "deliverance" prayers that even the faithful can offer; these are supposed to be most efficacious when offered by someone who has authority over the afflicted, e.g. a parent for a child. Also, holy water and blessed salt are very effective for the less dramatic diabolical manifestations.