Change is possible. We are capable as humans of embracing more and more sin and destroying our lives and those around us, or diligently practicing righteousness. The former is the natural state for the unsaved, as well as, for those believers who refuse to rely upon God through embracement of His Word.
But the question is often posited “how do I change?” The answer is simple and complex simultaneously. It is simple in that change is declared in the Bible as conformity to Jesus Christ. It is complex in that there are hundreds of ways in which humans need to change. A few examples are pride, fear, anger, strife, lying, ignorance, sexual misconduct, selfishness, etc.
So, if you know of someone who desires to change, or you yourself do so, the first place to begin is God’s Word. You need recognize that is truly sufficient to address all human issues. For example, while it may not talk about not looking at pornography on a computer, it does require us to not put worthless or vulgar things before our eyes (Psalm 101:1-3). Or, for those struggling with those who only desire to talk foolishly, 2 Timothy 2:16, 17 encourages limiting time with them.
Change is possible, but you must make use of the sufficiency of God’s Word.