Tune all strings down 1 step (D G C F)
Note that Eirik plays a 5-string, so it may occur that
I transcribe a part an octave higher...

Riff A
F   [-------------------------------------------------------
C   [-------------------------------------------------------
G   [--7-7-7-7--7-7-7-7--7-7-7-7--5-5-5-5--3-3-3-3--3-3-3-3-
D   [-------------------------------------------------------

F   --------------------]
C   --------------------]
G   --3-0-0-0--0-3-3-3--]
D   --------------------]
      !        !



Riff B
F   [--------------------|--------------------] 
C   [--------------------|--------------------]
G   [--7~~------3~~------|--7~~------3~~------]
D   [--------------------|--------------------]



Riff C
F   [--------------------|-----------------------]
C   [--------------------|-----------------------]
G   [--7~-------7~-------|--7~-------7~-(10-9-7)-]
D   [-(0)------(0)-------|-(0)------(0)----------]



Riff D (var. on Riff A)
F   [-----------------------------------------------
C   [-----------------------------------------------
G   [--7-7-7-7--7-7-7-7--7-7-7-7--7-7-7-7--3-3-3-3--
D   [-----------------------------------------------


F   -------------------]
C   -------------------]
G   -3-0-0-0--0-3-3-3--]
D   -------------------]