When you wish to call on my Son, you must simply call on Him to take you into His Mercy and leave the rest to Him.
Here is a special Crusade Prayer (133) A Call to return to God:
Dear Jesus, forgive me, an estranged soul, who renounced You, because I was blind.
Forgive me for substituting Your Love with useless things which mean nothing.
Help me to pluck up the courage to walk by Your Side, to accept with gratitude, Your Love and Mercy.
Help me to remain close to Your Sacred Heart and to never wander away from You again. Amen.
These Prayers, dear children, come with great Graces and those who recite them will be shown the Truth and their hearts will be filled with a great love, which they will never have experienced on Earth before now. Then their souls will be purified.