How is it possible to turn from your sins and what does that mean?
If you turn from something, it means you are turning to something or someone else.
The simple truth. If you turn to Jesus, you are turning from your sins. We are capable of wandering which is how sin is possible.
Thus says the LORD, "Even so they have loved to wander; they have not kept their feet in check. Therefore the LORD does not accept them; now He will remember their iniquity and call their sins to account."
Where there's a will there's a way. The will has to be great enough.
The Lord tells us exactly how through David in Psalm 119.
How can a young man keep his way pure?
By keeping it according to Your word.
With all my heart I have sought You;
Do not let me wander from Your commandments.
Your word I have treasured in my heart,
That I may not sin against You.
Blessed are You, O LORD;
Teach me Your statutes.
With my lips I have told of All the ordinances of Your mouth.
I have rejoiced in the way of Your testimonies, As much as in all riches.
I will meditate on Your precepts And regard Your ways.
I shall delight in Your statutes;
I shall not forget Your word.
Jesus is The Word that He speaks of in The gospel recorded by John in chapter 1.
In the beginning was the Word, and the Word was with God, and the Word was God.
Do not forget Him dear friends.