Repeat the positive ones, and they will eventually get louder than the negative ones. This is the thought behind daily affirmations: "I'm good enough, I'm smart enough, and dog-gone it, people like me."

I had a childhood where I was brought up to believe I was worthless. One tactic I used to overwrite those schema that imprinted in my personality from early life is to repeat what I believe about myself, like I'm a good person, etc. Eventually those pathways of believing I'm good were more comfortable than those of believing I'm worthless.