Tuning: Gb Db Ab Eb (1/2 step down)

All the other tabs I see here
just weren't completely what 
Dirnt played, so I hope this 
is closer than the rest.
Listen to the isolated
bass track for strumming patterns. 

Key:
h hammer on
p pull off
. staccato
^ marcato
x mute note
/ slide up
\ slide down
~ let ring

Intro
——X2 rest———X1
Gb———————|————4h5p4p0—|
Db———————|——55————————|
Ab———————|————————————|
Eb———————|————————————|


Verse 
X10
(Alternating, kinda)
1st,3rd,4th,5th,7th,8th,9th times
————.——————————.———————————.——————>                      
Gb——————4h5p4p0————————————————4h5>
Db——5—55———————————4h5p4p0—2—22———>
Ab—————————————5—55———————————————>
Eb————————————————————————————————>
———————————.—|     
Gb>——————————|
Db>——————————|
Ab>3—333—550—|
Eb>——————————|

Alternate Verse
2nd,6th,10th times
————.—————————^—.—————————x——————>
Gb——————4h5p4—7———————————————4h5>
Db——5—55————————————4h5p4—2—22———>
Ab——————————————5—55—————————————>
Eb———————————————————————————————>
            
————————————.——10th time only
Gb>——————|———|——————————|
Db>——————|———|——————————|
Ab>3—333—|550|/(7)*—————|
Eb>——————|———|————*(12)\|

* slide up to 7 on Ab string, then slide down from 12 on Eb string. May take practice to make fluent *

Chorus
X1
Gb————————————————————————>
Db——————————————————5h7p5—>
Ab———————————————————————7>
Eb——55555555—7—8—8—8——————>
——————————————————————————^———|
Gb>———————————————————————5p4—|
Db>———————————————————————————|
Ab>———————————————————————————|
Eb>55—555—555—7—8—8888888—————|

Then Verse again, playing the alternate on the 2nd, 6th, and 10th  times, and sliding on the 10th time, just as before

Then Chorus, just as before

Then Verse, only 4 times, the alternate on the 2nd and 4th times, and sliding after the 4th time

Then Chorus, just as before

Then verse, only  3 times, and never the alternate

End on this variation of the Verse
———.—————————^——.————————.—————————|
Gb—————4h5p4—7—————4h5p0——————4h5——|
Db—5—55—————————2—22—————2—22——————|
Ab————————————————————————————————3|~~
Eb—————————————————————————————————|

And that's it! Enjoy!

The isolated bass track: