The first measures of the song are very easy to play. For measures 9 to 11 and 13 to 15 things get more complicated. You will put your middle finger on the G string at fret 9. Then, you will place your pinky finger on D string at fret 12. Your ring finger will go on fret 10 and your index will take fret 9 and fret 7. Et voila, that is the position. I hope I'm clear in my explanation.