Here is an excerpt from the Little Office of the Immaculate Conception:
Holy Mary, Mother of God, I firmly believe in thy Immaculate Conception. I bless God for having granted thee this glorious privilege. I thank Him a thousand times for having
taught it to me by the infallible voice of the Church. Receive my heart, O Immaculate Virgin; I give it to thee without reserve; purify it; guard it; never give it back to me,
preserve it in thy love and in the love of Jesus during time and eternity. AMEN.
V. Thy name, O Mary, is as oil poured out.
R. Thy servants have loved thee exceedingly.
Let us pray.
O God, Who by the Immaculate Conception of the Virgin, did prepare a worthy habitation for Thy Son: we beseech Thee, that as in view of the death of that Son, Thou didst preserve her from all stain of sin, so Thou wouldst enable us, being made pure by her intercession, to come unto Thee. Through the same Christ Our Lord. AMEN.