I think I understand what you mean. I wish I could change many aspects of my personality, but I think what mostly hinders my progress is that I don't know what my goal clearly is as of now. But I feel that there is too much making up my personality that was born from unfortunate circumstances or lack of standard and developing experiences. There's a lot that's off about my personality while I also feel, I suppose, "undefined," which makes me feel disconnected and uneasy when interacting with people.
I'm not sure if it's possible to change your personality really, but I'm starting by trying to rid myself of the things I feel shouldn't be there. Doing that still feels difficult, but at least it's a comprehensible goal. Trying to gain the attributes that I would like after first figuring out what those should be seems like the more difficult part. Maybe trying to manufacture my personality to such a degree isn't healthy, but I wouldn't really know.