Standard tuning
Guitar 1
E--------------
B--------------
G--------------
D-3-2--2--2---0 (keep repeating throughout intro)
A-2-2--0--0---5
E-0-0--1--2-0-3
Guitar 2
E-------------
B-------------
G-4h5-2--4-4h5-2--4h5-2-0--5-4
D-------------
A-------------
E-------------
Guitar 3
E-7h8-5--7-7h8-5--7h8-5-3--8-7
B-------------
G-------------
D-------------
A-------------
E-------------
I`m not totally sure about guitar 3 but it sounds good.
Metallica kicks ass!