theres a lot of controversy over this song but this sounds right to me

main riff
G|------------------------------|
D|------------------------------|
A|-----6--7--9/4-----6--7--9/4--|
E|--4-------------4-------------|

there is no bass from 2:04 - 2:20

at 2:20 it does this and then goes back into the main riff

A|-10/4-|

riff b  play this twice at 0:56, once at 2:27, play half of it at 2:39, and once at 3:01. 
the bass ends abruptly after the slide down at 3:03.
G|--------------------------------|
D|--------------------------------|
A|-----6--7//15/4-----6--7//15/4--|
E|--4-------------4---------------|