This is the main riff: 

|----------------------------------------------------| 
|----------------------------------------------------| 
|----------------------------------------------------| 
|-------7-5v~-----5~-----5~--------5-/7v~~~~---------| 
|-5h6------------------------------------------------| 
|--------------6~-----5~-----------------------------| 


Now through out the song there are a couple variations 

Variation 1: 
|----------------------------------------------------| 
|----------------------------------------------------| 
|----------------------------------------------------| 
|-------7-5v~-----5~-----5~--------5-5-5~~~~---------| 
|-5h6------------------------------------------------| 
|--------------6~-----5~-----------------------------| 


Variation 2: 
|----------------------------------------------------| 
|----------------------------------------------------| 
|----------------------------------------------------| 
|-------7-5v~-----5~-----5~--------5~~---------------| 
|-5h6------------------------------------------------| 
|--------------6~-----5~-----------------------------|