I think this is the right version of the intro. some of the other ones just didnt seem right.

Drop-D Tuning

b - bend
[] - play that note on the bend

play the riff for both guitars 4x

1st Guitar

e|--------------------------------------------------------|
B|--------------------------------------------------------|
G|--------------------------------------------------------|
D|-------------------------------------------------5b[6]--|
A|----------3-----------6b[7]----------3------------------|
D|-5--5-3-5---5-3-5--5--------5--5-3-5---5-3-5--5---------|

2nd Guitar

e|--------------------------------------------------------|
B|--------------------------------------------------------|
G|--------------------------------------------------------|
D|--------------------------------------------------------|
A|----------3---------------------------3-----------1--1--|
D|-5--5-3-5---5-3-5--5--4b[5]--5--5-3-5---5-3-5--5--1--1--|