The song Playing : http://youtu.be/WfkLO3J88K0

Normal Tuning
G|
D|
A|
E|


You can play the riff like this

Intro
|---3--5-5----3--5-5---3--5-5--------------|
|---3--5-5----3--5-5---3--5-5--------------|
|------------------------------------------| x4    -|
|-4-4----6-6---------------4>>--6>>------|

|--------------------------------------------------------------------------|
|--------------------------------------------------------------------------|
|--------------------------------3-3-3-3-3---------------------6-6-6-6-6-6-|
|-4-4-4-4-4-6-6-6-6-6--3-3-3-3-3-----------4-4-4-4-4-6-6-6-6-6-------------|

|-----------------|
|-----------------|
|-----------6~----|
|-4~---6~---------|

outro
|---3--5-5----3--5-5---3--5-5--------------|
|------------------------------------------|
|------------------------------------------| x4
|-3--------3---------3--------4--4-4-4-7-7-|
  s p  p   s  p  p   s p  p   s  s s s s s