Riff 1
G|-----------------------------------------------------|
D|------------------------5----------------------------|
A|----1-1-1------3-3-3------5-5-5----3-5-3-1-----------|
E|--3----------3-----------------------------3---------|


Riff 2 comes in around 0.45 sec
G|-----------------------------------------------------|
D|-----------------------------------------------------|
A|--------1---1-3---1-3-1-3-5-----1---1---3-3-5-3-1----|   X6
E|--3---3---3-------------------3---3---------------3--|


Riff 3 
G|-----------------------------------------------------|
D|-----------------------------------------------------|
A|--------1---1-3-3-1-3-----5-----1---1---3-3-5-3-1----|   X2
E|--3---3---3-------------------3---3---------------3--|


Riff 4 
G|-----------------------------------------------------|
D|------------------------5----------------------------|
A|----1-1-1------3-3-3------5-5-5----3-3-5-3-1---------|
E|--3----------3-------------------------------3-------|

Just listen for changes in the song riff 1 can be played as riff 4 as both are very simular