Well, here's the main riff. It sounds a bit like that: 
 
|-----------------------------------------------| 
|-----------------------------------------------| 
|----------------------3---------------------3--| 
|--3---5-5-5-5---3-3---3---5---5-5-5---3-3---3--| 
|--3---5-5-5-5---3-3-------5---5-5-5---3-3------| 
|-----------------------------------------------| 
 
|-----------------------------------------------| 
|-----------------------------------------------| 
|----------------------3------------------------| 
|--3---5-5-5-5---3-3---3---5---5-5-5---3-3--5---| 
|--3---5-5-5-5---3-3-------5---5-5-5---3-3--5---| 
|-----------------------------------------------|