Catechism of the Catholic Church §1519 — excerpt
The celebration of the sacrament includes the following principal elements: the "priests of the Church" - in silence - lay hands on the sick; they pray over them in the faith of the Church - this is the epiclesis proper to this sacrament; they then anoint them with oil blessed, if possible, by the bishop.
This translation is under copyright, so only the cited words are quoted here. Follow the link for the full text. Translation: English translation of the Catechism of the Catholic Church, 2nd ed. (Libreria Editrice Vaticana), as posted at vatican.va.