That part you're referring to is actually a harmonized riff with two guitars playing. The lower harmony would be played like this (excuse the pseudo-tab):

E----------------------------------------------------------

B----------------------------------------------------------

G-------------------------------------------7------7--9---

D----------4--5--4--5--7--5--7--9--7--9------9---------

A-7--5--7-------------------------------------------------

E----------------------------------------------------------

The higher harmony is up a fourth. Hope that helps.

Doug