Main riff 1 (higher) 
G|--------------------|--------------------|--------------------|--------------------| 
D|-----------0-4-5-6--|--------------------|---------------~7-5~|-----9----7h9-------| 
A|-7---5-7------------|------5-7-----------|-0-5-6-7------------|-5/7---7-------5--6-| 
E|---7---------------0|----------4--5--6--7|---------0----------|--------------------| 

The last bar leading to riff 2 (always switch the last two notes):  A|-----6--5-| 

Main riff 2(lower) 
G|--------------------|--------------------|--------------------|--------------------| 
D|--------------------|--------------------|---------------~4-2~|-----6----4h6-------| 
A|-4---2-4-----6-7-8--|--------------------|---2-3-4-2----------|-2/4-----------2--3-| 
E|---4---------------9|------7h9-1--2--3--4|-3------------------|--------------------| 

Variations(the last two bars - the frist two are always the same): 

Var. Of main riff 1 (v) 
G|--------------------|-----9-7---------------| 
D|---------------~7-5~|----------0-7-8-9------| 
A|-0-5-6-7------------|-5/7---------------5--6| 
E|---------0----------|-----------------------| 

Var. Of main riff 2 (V) 
G|--------------------|-----6-4---------------| 
D|---------------~4-2~|------------4-5-6------| 
A|---2-3-4-2----------|-2/4---------------2--3| 
E|-3------------------|-----------------------| 

 Another special var. of riff 1 (s) 
G|-----------------4/12|-14--12h14--12--7-8-9--------| 
D|-----------~7-5~----|------------------------------| 
A|-0-5-6-7------------|-----------------------5--6---| 
E|---------0----------|------------------------------| 

 Another special var. of riff 1 (S) 
G|--------------------|--------7h9------------| 
D|-----------------5-5|-----------------------| 
A|-0-5-6-7------------|7-7-7-7------7h10--5--6| 
E|---------0----------|-----------------------| 


************************************ 

| h  Hammer-on 
| ~  Vibrato 
| /  Slide up 

************************************