How do you edit your infobox on a wiki

Hi, I'm wondering, How do you edit your infobox on a wiki.
I chose the infobox carater (car-rector) (idont care how you spell it)
and the questions are (well not questions but, headings I guess, wikia people will know what I mean) title, image, image width, image caption, position, age, status, height and weight. I wanna change some of them like, position, status and weight. and also add more, I would love to know how, or even create my own, if you know how please tell me. -bpste1