There are only two riffs in this song. The first one is the main riff which is in the intro and mostly through out the song. The second one only comes in during the bridge.

Main Riff
G0000000033333333----------------
D----------------3333333311111111
A--------------------------------
E--------------------------------

Bridge
G00-000-----------------------
D-------11-111-2-2-2-2-00-0---
A-----------------------------
E-----------------------------