When you change your actions/behaviors, you change the biochemistry of your brain. Neurotransmitters start firing in new areas, changing the function of your brain. Changing the function over time will change the structure of your brain, new pathways are formed. This is how you change your brain.
Your Brain is changed every time you learn something new.
Listen to Brain Researcher Dr. Lara Boyd from University of British Columbia in a TEDx talk titled “After watching this, your brain will not be the same.” In addition to describing the process of how to change your brain, she also talks about the common misconceptions about the brain, and how different people learn differently.