Thanks for pointing out the „over time“ aspect! Many people with problems want to do some kind of 30-day-program to get rid of problematic traits. Yet it might take years to really change how you think and what the outcomes are. I, for one, have had active bad personality traits that were holding me back (I wanted to overcome them, but couldn‘t), yet when in my early 30s, I came into a peer group that was very supporting, I finally got the grip and was able to reveal the better parts of me and had good success in life (and boy, life feels so good now). I certainly have not deleted the bad traits, but learned to work around them so they do not affect me much. Time and people were my key factors. Who wants to join a 3-year-program... does not sound that sexy, but is what it often takes to change.
Yes, it definitely takes time. You're right, it requires that you "change how you think". From my experience, the easiest way to do this is to surround yourself with people who have traits you admire. They'll rub off on you!