There are a few ways to play the
first note of the intro:
          E---------------
          B---------------
          G---------------
          D---------------
          A---------------
          E-0/(-1)/0------
With this way, the negative 1 is actuall Eb,
but if you're playing in standard tuning, 
you'll have to either adjust the peg on the E
string every time you play that note, or use
your wammy/tremolo bar on your guitar.

Or you could tune your low E string to D:
          E-------
          B-------
          G-------
          D-------
          A-------
          E-2^1^2-
Which is just a sliding/hamer style.

The other way you can play it, the 
one I prefer is to bend:
          E---------
          B---------
          G---------
          D---------
          A---------
          E-1pbr-b--   (pbr-b: pre-bend, release, bend)

How you pull this one off is simple.
Just give the note a full bend right
away, let up to go back, then
give it another full bend.   (pbr-b: pre-bend, release, bend)

The rest of the intro:

E------------4-4--------------------|
B------5-4-5------------------------|
G----------------4-4^6--------------|
D----------------------2-4-4^6------|
A-----------------------------------|
E-----------------------------------| 2x



Thanks Axe, for helping me with the bend vocab.  :)