Below is the basic part for the main riff:
What you’re hearing is 3 guitar parts. The 1st plays the riff as illustrated above. The next guitar is playing a A, C#, D, Dm. The chords change with each measure. The 3rd and final guitar is playing the above melody an octave higher. To do this you’ll want to play everything the same, only 12 frets higher. For example the first note will be on the 14th fret (2+12=14).