Here's the Bassline

G|---------------------------------------------------------------------------|
D|---------------------------------------------------------------------------|
A|-----------------6--------4------------------------------6---------8-------|
E|6------4-------------------------------6--------4--------------------------|

G|----------------------------------------------------------------------------|
D|----------------------------------------------------------------------------|
A|-----------------4-------4-----------------------------------4---4----------|
E|6-------4------------------------------2------2-----------------------------|

That's it except for sometimes the first bar goes like...
G|--------------------------------|
D|---8--8----6--6-----------------|
A|----------------6--------4------|
E|6-------4-----------------------|