i play this alot in my band so i think this is mostly right
after guitar plays first bit once play this

g:----------------------------------------------------------------|
d:----------------------------------------------------------------|    x3
a:----------------------------------------------------------------|
e:5-5-5555555555-0-0-0000000000-5-5-5555555555-0-0-0000000000-----|

then just before the chorus play this

g:-------------------------------------------------------|
d:-------------------------------------------------------|
a:-------------------------------------------------------|
e:999999-555555-000000000000-999999-4444444-55555555-555-|

chorus

g:---------------------------------------------------------------------|
d:---------------------------------------------------------------------|
a:77777770-----------------------------------77777777------------------|
e:---------77777777-555555555555555-99999999---------77777777-55555555-|

g:-------------------|
d:-------------------|
a:---------99999999--|
e:99999999---------5-|

play this after the 2nd chorus


g:--------------------|
d:--------------------|     x2
a:1-3----3-1----------|
e:----3-4----3-4------|