This has to be my all time favorite bassline. Enjoy, rate so I know how I did.

Verse (count it off so you know how many times to do it, repeat it it that order)
----------------9999|-------------------
----555-777---------|----555-777--------   
777---------555-----|777---------555-777
--------------------|-------------------

Pre Chorus
-------------
----55---55--
777----5----5
-------------

Chorus (on '753' slide your index finger from 7th fret to 3rd fret, then hit 5th then open, do this all really fast.)
-----|----|-------|-----|-------|-------|
-----|----|-------|-----|-------|-------|
7-5-7|-5-5|-------|-----|-------|-------|
-----|7-7-|753-5-0|3-0-3|0-5-3-5|5-7-5-7|