Song is in Standard E or in Drop D but for the intro you'll only need the G string.

So here it goes.

First part:

E----------------------------------------------------------------------------|
A----------------------------------------------------------------------------|
D----------------------------------------------------------------------------|
G--0--12--0--10--0--8--7~--0--7--0--8/10--0--7/8--7~-------------------------|
B----------------------------------------------------------------------------|
E----------------------------------------------------------------------------|

Second part:

E----------------------------------------------------------------------------|
A----------------------------------------------------------------------------|
D----------------------------------------------------------------------------|
G--0--7--0--5/7--0--3/5--3~--0--3--0--5/7--0--3/5--3~------------------------|
B----------------------------------------------------------------------------|
E----------------------------------------------------------------------------|


That's all. Source was this video :
http://www.youtube.com/watch?v=zayG1oUyeUM

Here i could see what he is playing. It's 99% accurate.

Hope you like it.

~ means vibrate the string.
/ means slide from a fret to another fret.