One of the spiritual works of mercy is to pray for the Faithful Departed, who can do no more for themselves. There are plenary indulgences assigned to this season, outlined in the Enchiridion, which you may obtain for the Holy Souls in Purgatory:
1. A plenary indulgence, applicable ONLY to the souls in purgatory, may be obtained by those who, on All Souls Day, piously visit a church, public oratory, or for those entitled to use it, a semi-public oratory. It may be acquired either on the day designated as All Souls Day or, with the consent of the bishop, on the preceding or following Sunday or the feast of All Saints. On visiting the church or oratory it is required that one Our Father and the Creed be recited.
2. You may make a visit to a Cemetery or Columbarium. A plenary indulgence is applicable to the souls in Purgatory when one devoutly visits and prays for the departed. This work may be done each day between November 1 and November 8.
To obtain a Plenary Indulgence, one must fulfill the following requirements:
1. Make a Sacramental Confession,
2. Receive Holy Communion,
3. Offer prayer for the intention of the Holy Father.
All these are to be performed within days of each other, if not at the same time.