This is just the tab for the walkdown in the intro. I couldn't find an accurate one and 
I think this is correct.

Tuning: standard

e|-------------------------------------------------------------------------------|
B|-------------------------------------------------------------------------------|
G|----3-2------------------------------------------------------------------------|
D|---------3-0-------------------------------------------------------------------|
A|-------------------------------------------------------------------------------|
E|-------------------------------------------------------------------------------|

For the rest of the intro I use G, D, and Em, then this is at the end.  It continues 
like this through the first verse.