The first part is very easy and after the difficulty is progressive. You will need several weeks to learn it, in particular the last part but the song sounds awesome.
Play the song very slowly at the beginning and you will increase the speed when you will master the part. In the part 2 and after, you must reach the keys with your thumb and pinky. It is an excellent exercice for your fingers, but if you can't, just play one note.
Use the sustain pedal for this song. You can let it depressed all the time at the beginning. With more experience, you will hear that the sound is better when you release and depress the pedal just before you start a new serie of notes.