Based on the playthrough by Teloch: https://www.youtube.com/watch?v=e_9MAKZ5FZg

1: Riff 1 is pretty straight-forward but it 
has a little specialty to it - and that's hitting the open D-string twice between the end and the beginning. And make sure to l
et that minor chord ring when you're re-hitting the open D-string with the fourth beat in the first bar. And it seems like you 
don't have to hit the open string too hard on that one. Otherwise you will get too much of a droning noise and we don't want th
at here.

5-38: I wrote these riffs as 6/4. But if it helps you, you can also think of them as 12/4 for two bars. And of cour
se you can also think of them as 4/4 for six bars. When you play along to the song you may notice that the drums are also shift
ing between different "feels". For example Riff 2 is often played with a 4/4-feel on the drums. Riff 3 has more of a 6/4-feel, 
I guess.

23: The transition here seems to be a mix between Riff 2 and Riff 3.

30: It is possible that there's some slight
 P.M. going on at the end of that riff - at least that's what his hand motion is indicating to a certain extent. 

38: This b
reak is a bit tricky due to the timing and I'm not entirely sure it's correct that way. Nevertheless: When you play along to th
e song, make sure to end on the third accented snare-drum. The timing/feeling of the quarter rest in bar 39 is the same as in R
iff 6 - maybe try to get comfortable with that one first and then come back to the break in bar 38/39.