The priest is to sacrifice them, one as a sin offering and the other as a burnt offering. In this way the priest will make atonement for the man before the LORD because of his discharge.
Jewish Publication Society of America Version (JPS1917) - Leviticus 15:15 >And the priest shall offer them, the one for a sin-offering, and the other for a burnt-offering; and the priest shall make atonement for him before the LORD for his issue.