What sort of therapy could help a person become more extraverted?

Is there any therapy that is considered effective for changing a person’s personality from introversion toward extraversion in the absence of any specific diagnosable disorder?

I am able to find many resources on treatment modalities that have been found to improve social function in people with certain specific disorders for which introversion is often a symptom, such as autism, depression, and schizophrenia, but I’m interested in the case of someone who doesn’t have any specific disorder per se, but wants to become less introverted in order to build relationships, social capital, professional stature, etc.

As an analogy, remedial/developmental reading educators often distinguish between people with specific learning disorders such as dyslexia who often need a diagnosis-specific intervention versus people who just didn’t get the opportunity to learn earlier, and thus respond well to general pedagogical techniques.