OK, I'm not proud to tab this, but the bass line is just so *** catchy!
AND SIMPLE!  I figured this out in about a minute.

Here's the main riff:

 G  |---------------------2-2-----|----------------------------|
 D  |*----------------------------|--------------------2-2----*|
 A  |*----------------------------|---------------------------*|
 E  |---3---3---5-----------------|--0--0--0--0-0--------------|