This is my first tab, but I think I got it for the most part. Technically this is in
open D tuning but really all you need is to tune down the low E a whole step and the G a
half step to F#. Becky varies fingerings throughout the song, but basically this is what it is-
Riff 1
E |---------------------------------------------|
B |---------------------------------------------|
Gb|---------------------0------0------0---------|
D |-------0------0--------------------0---------|
A |--3-2-0--3-2-0--3-2-0--3-2-0--3-2-0----------|
D |---------------------------------------------|
[ Tab from: http://www.guitaretab.com/t/the-pack-ad/265344.html ]
Riff 2 -I think she uses a slide but you don't really need one.
E |---------------------------------------------|
B |--------------------------------3------------|
Gb|---------------------------------------------|
D |--12---10---12-12-12----5-3-2-2-0------------|
A |--12---10---12-12-12----5-3-2-2-0------------|
D |--12---10---12-12-12----5-3-2-2-0------------|
E |---------------------------------------------|
B |---------------------------------------------|
Gb|---------------------------------------------|
D |--12---10---12-12-12----15-15-15-15----------|
A |--12---10---12-12-12----15-15-15-15----------|
D |--12---10---12-12-12----15-15-15-15----------|
E |---------------------------------------------|
B |--------3----------3-------------------------|
Gb|--------0----------0-------------------------|
D |--3-2-2-0----3-2-2-0-------------------------|
A |--3-2-2-0----3-2-2-0-------------------------|
D |--3-2-2-0----3-2-2-0-------------------------|
Pretty much that. You'll have to make up variations or whatever. Hoped this helped though.