This is the bass-line that goes on during most of the song.

G|---------------------------------------------------------------------------|
D|---------------------------------------------------------------------------|
A|--------------------3-0303-5-5-5-557-888-----------------------------------|
E|-3-3-3-3-33-1-1-1-1----------------------8-858-----------------------------|

An alternative version with different finger positions on the end:

G|---------------------------------------------------------------------------|
D|---------------------------------------------------------------------------|
A|--------------------3-0303-5-5-5-557-888-3-0303----------------------------|
E|-3-3-3-3-33-1-1-1-1--------------------------------------------------------|

I haven't figured out the part that's played during the "solo" during the live-performance on Jimmy Kimmel.
The bass follows the electric guitar and ukelele instead of doing something that resembles the main line 
like the album-version. So if anyone has a clue about that one please comment.