Not sure what tuning Flipper used, but this is in standard.

The main "verse" riff:
|------------------------|
|-------2-4---------4-3--|
|-0-2---------0-3--------|
|------------------------|

The "chorus" riff:
|-------------------------------------|
|-3-33-3-32-----------5-------3-------|
|----------0-3-33-33-3--2-3-5---0-2-3-|
|-------------------------------------| x2

There are several variations on both throughout the song, listen to it a few times to 
the idea.