Is it possible to change the position of the ear on the head?

An exam by a board certifed plastic surgeon would be required to answer your question. It all depends on which parts of the ear need to be made larger.

All scars go through a healing stage, with most scars taking a year to a year-and-a-half to mature fully.  Redness decreases and scar tissue softens and flattens as healing takes place. Younger people tend to be more exuberant scar formers than people in their 60s and older....

Although it is not “real fighting”, if I were you I would not engage in “sparring/training” for at least 3 months after the otoplasty procedure performed. Even then, I would suggest that you have the area covered/protected as you spar. Your plastic surgeon will be your best resource when it come...