Is it possible for an introvert to change to an extrovert? If this is possible, How?

An introvert cannot change completely to an extrovert and vice versa. However,it can be modified.
There is what we called( outgoing introvert) and (shy extrovert).
If as an introvert, you want to start socialising and behave like an extrovert, the best you can become is an outgoing introvert,you will just be more outgoing,but you will still need to be alone to recharge like introverts does.Likewise,extroverts do change sometimes due to quiet neighbourhood or marriage (it mellows some people)e.t.c they can only become shy extroverts.They will still need to be around people to recharge,they cannot become an introvert completely.

Above all being filled with holy spirit do modify people's character.so,you cannot change completely because it is an inborn trait.