Not sure about the original version (never heard it), but the Cake version is quite easy to play on the guitar, with the following chords:
   Am     
At first I was afraid.
      Dm
I was petrified.
       C         
I kept thinking I could never live
            G
Without you by my side.
           F
But then I spent so many nights
              B
Just thinking how you'd done me wrong.
       E
I grew strong.
          E
I learned how to get along. 
The chorus and bridge also follow this chord progression.

The bass line is a lot more intricate, with the bass playing scales of the above chords. Add the trumpets, drums and vocals, and you have a pretty damn good song.

For a little bit of trivia, the beginning of "I Will Survice" (Am, Dm, C and G) is exactly the same as the main riff in Guns N' Roses - Don't Cry. Who would have thought that's this is a popular chord progression? :-)