I've played this a couple of times and it sounds right

intro

--------------------------
------------0-3-0---0-----
-0---0------------2-------    Repeat Several Times
---0---0-2-------------2--
--------------------------
--------------------------


Riff 1

G           G
-3----------3
-3----------3
-0--2-4-2-0-0     4 Times
-0----------0
-2----------2
-3----------3


Riff 2

D           Em
-2----------0-----------
-3----------0-----------
-2----------0-----------   3 Times
-0---0------2-----------
---2---2-0--2-----------
------------0-2-3-5-----

Riff 3

--------------------------------------
--------------------------------------
--------------------------------------    4 times, but on the 4th time
--------------------------------------    do this:
--2-3-2-3-2-3-2-----2-3-2-3-2-3-2-----
----------------3-----------------3---

                                           D -----------------2-2-2-2-0-------
                                           A --2-3-2-3-----------------2-0----
                                           E --------------------------------