In the absence of a priest or deacon, an instituted acolyte may expose and repose the Blessed Sacrament for a period of adoration, though he may not give Benediction.

Exposition

Before the service, the acolyte ensures that there is a host in a luna in the tabernacle; a clean corporal should be open in the center of the altar; a monstrance should be placed on the altar, open, facing north, and just to the left of the corporal, an order of service should be ready in the sacristy, or else placed at the foot of the altar, candles should be lit. The acolyte vests in cassock and surplice for simple exposition; he will not need a humeral veil; as he will not be giving Benediction. In exposition by an acolyte, incense is not used.

The acolyte enters the sanctuary, genuflects at the foot of the altar and ascends to the footpace. Upon opening the tabernacle, he genuflects again, removes the luna containing the Blessed Sacrament, places it into the monstrance, and positions the monstrance int he center of the altar. He returns to the foot of the altar, where he genuflects, then kneels. The acolyte then intones the O Salutaris Hostia. After the hymn, the acolyte rises, genuflects and takes his seat in the chancel or sedilia, or he may retire to the sacristy if the adoration is to be a prolonged one. if he remains, he may lead the Divine Office, or any devotions that may occur.

Reposition

Following a suitable time of adoration, the acolyte returns to the foot of the altar, genuflects, then kneels to intone the Tantum Ergo. He recites the proper versicle and Collect for Reposition of the Blessed sacrament, followed immediately by the Divine Praises, all as found in the Rite of Exposition and Benediction of the Blessed Sacrament.

The acolyte rises, genuflects, and ascends to the footpace; at this point he might intone a hymn of praise. he first turns the monstrance in place, then he opens the tabernacle, removes the luna from the monstrance and returns it to the tabernacle, which he then closes.

the acolyte then moves the monstrance off of the corporal, which he then folds, then he returns to the foot of the altar once again to genuflect, and lever the sanctuary reverently.