How does someone go about changing their personality?

This isn't specific to career, but I thought there could be someone who would relate to it and I can find answer to this here.

I wouldn't say I am an extrovert, in the sense, I do like to be among people, but I enjoy one on one conversations more than talking to an unfamiliar group. I like to listen to people than keep on talking.

I do want more people in life, but I just till date have not done the extroverty stuff like meeting acquaintances once a while, calling people home etc. And I see, the higher we go in our careers, we do need to be extroverts, network with people etc. And in personal life, I feel I don't have a social life at all.

My mother's an extrovert, my father is like me. My mother knows so many people when she goes out in the street. People come to our house for her, there are get togethers, etc. I have never seen that for my father. Since I have seen both sides, I personally want the kind of personality which has ability to make impression, friends etc.

My fear is that my entire life would go by and I would end up alone. I am sure such unhealthy personal life would impact my professional life, even if it doesn't, what's the point in having a career if I don't have people in my life to experience it with?

I have tried asking these social extroverts in my life on how do they do it but its like they were born with these skills and they have no idea how its done, its just something natural and obvious to them and completely oblivious to me.

How do I become a better personality? Like, not just professionally, but develop personal relationships as well especially when you have not done a great job till age 26 on this and it totally feels like starting out very late in life with this.