How can a self-taught piano player get a musical score into a movie?

Its who you know

Film scoring is a difficult business to get into, as with any media job, its all about contacts, if you know the right people you can get yourself listened to. If you have written music already, which you would like to try and get into the score of a film then my advice would be to go to smaller independent film companies with demo tapes. Although production companies generally like to fit the music around a film, or have the music written in the post production process during editing, so existing scores are not as usefull.