The whole song is based around a main riff it is quite simple

Tunng:DGDGAD (open G)

x=slap the strings with thumb in a percussive style
h=hammer ons
/=slide up


Intro
D|--------------------------------------------------------------------|
A|--------------------------------------------------------------------|
G|--------------------------------------------------------------------|
D|--------------------------------------------------------------------|
G|--x-4-x-0h5h7x5-------x-4-x-0h5h7x5-------x-4-x-0h5h7x5-------x-4-x-|
D|5-x---x------x----0h5-x---x------x----0h5-x---x------x----0h5-x---x-|

D|----------|
A|----------|
G|-5/7-5/7-5|
D|----------|
G|-5/7-5/7-5|
D|----------|

Rest of the Song
D|--------------------|
A|--------------------|
G|--------------------|
D|--------------------|
G|----x-4-x-0h5h7x5---|
D|0h5-x---x------x----| repeat until end


I haven't heard the full recording, just a live verision on youtube, he might add some 
bits in but you should be able to get away with it like this