Figured this out by ear. Amazing song.

Standard Tuning

Riff 1
|---------------------------------|
|-----5-------5---6---5-------5h6-|
|---7---7---7---7---7---7---7-----|
|-7-------7---------------7-------|
|---------------------------------|
|---------------------------------|

Riff 2
|---------------------------------|
|-----6-------6-------6-------6---|
|---7---7---7---7---7---7---7---7-|
|-8-------8-------8-------8-------|
|---------------------------------|
|---------------------------------|

Riff 3
|-----8-------8-------8-------8---|
|---6---6---6---6---6---6---6---6-|
|-7-------7-------7-------7-------|
|---------------------------------|
|---------------------------------|
|---------------------------------|


It repeats in a pretty simple pattern: 1,2,1,2,1,2,3,2,3,2

And that's it, at least for the guitar.