Let us offer ourselves and lift up the whole world to be immersed in the boundless Divine Mercy of our Lord Jesus Christ.
Here are some background information.
This can be prayed as a Divine Mercy Novena.
Here is a guide to the Chaplet prayer:
Start from the center, going to the left, counterclockwise.
[1] The Sign of the Cross
[2] Optional opening prayers
You expired, Jesus, but the source of life gushed forth for souls, and the ocean of mercy opened up for the whole world.
O Fount of Life, unfathomable Divine Mercy, envelope the whole world and empty Yourself out upon us.
[3x] O Blood and Water, which gushed forth from the Heart of Jesus as a fount of mercy for us, I trust in You! (pray this line 3 times)
[3] 1 Our Father
[4] 1 Hail Mary
[5] The Apostle's Creed
[6] On the Our Father beads, say the following
Leader: Eternal Father, I offer to You, the Body and Blood, Soul and Divinity of Your dearly beloved Son, our Lord Jesus Christ,
All: in atonement for our sins and those of the whole world.
[7] On the 10 Hail Mary beads, say the following
Leader: For the sake of His sorrowful Passion,
All: have mercy on us and on the whole world.
[8] Repeat [6] and [7] for the remaining decades.
[9] All: [3x] Holy God, Holy Mighty One, Holy Immortal One, have mercy on us and on the whole world (pray this line 3 times).
Optional closing prayer
[10] All: Eternal God, in whom mercy is endless and the treasury of compassion inexhaustible, look kindly upon us and increase Your mercy in us, that in difficult moments we might not despair nor become despondent, but with great confidence submit ourselves to Your holy will, which is Love and Mercy itself. Amen
End by the making the Sign of the Cross.
Source: How to recite the Chaplet prayer