There are two things to be aware of: 1) The Church offers a plenary indulgence on this day. 2) Jesus promised special graces on this day. The indulgence and the promise are similar, but not identical.
1) The plenary indulgence: This requires confession (up to 20 days before or after), communion (a couple days before or after), prayers for the Pope (Our Father, Hail Mary), no attachment to any sin, and the specific "work" is the mercy devotions. The devotions are those held in common in the church, or before the tabernacle to pray an Our Father and the Creed and "Jesus, I trust in you".
2) The promise of Jesus: That any who confess (up to two weeks before) and receive communion on Divine Mercy Sunday itself (Our Lord does not say that the Saturday evening Mass counts) trusting in his mercy, will have not only their sins but even all the punishment of purgatory will be completely washed away. This is the perfect renewal of the graces of baptism -- and it does not require complete detachment from all sin, but only that we trust in his mercy!
Divine Mercy Sunday Schedule
9 AM - Solemn Mass with incense
11:30 AM - Low Mass, no incense
1 to 3 PM - Confessions (only Father Ryan available)
3 to 4 PM - Solemn Adoration and Divine Mercy Devotions
[Also, we have our Adoration Breakfast in the parish gathering area all morning!]