I used to be really shy around people. I joined theatre and a few other activities and they totally brought my inner-friendliness. Find something you really enjoy, become friends with people that enjoy similar things c:
Before I continue, i will add that being introverted isn't something to be ashamed of, and it isn't always necessary to be shameful of such things. Finding similar activities is the easiest way i have found, and a simple 'what music do you like' or 'did you see pacific rim, did you like it?', but don't ask a question like 'what sports do you play', as unless you play sports, you will feel belittled and uncomfortable. Basically, don't ask questions when their answers require the answer(er?) to reveal physical or educational advances over you.