uhuh Objection, I agree with arbygil. In addition, it seems highly unlikely that one who is introverted at core would exchange that for extrovertion.
There are pro's and con's with both and like Milon said, as he wishes to have more extroversion at times as it would be handy, hence his energy would still be attained otherwise.
It does not seem like a simple process as one would have to transform all functions into the other, which would furtherly mean that oen would be going against everything with oneself.