This is not the full song
and I don't have a 7-string guitar.
but you can play the part before the jibberish and bag pipes standard tuning.

e|-----------------------------|
B|-----------------------------|
G|--------8------------9----8--|
D|-----------------------------| X2
A|-----------------7-----------|
E|--7----------7---------------|

e|-----------------------------|
B|-----------------------------|
G|------4----4--------6----6---|
D|-----------------------------|
A|-----------------------------|
E|--4----4--------5----6-------|

e|-----------------------------| \
B|-----------------------------| |   
G|--------8------------9----8--| |Play this seperate before the next part
D|-----------------------------| |
A|-----------------7-----------| |
E|--7----------7---------------| |
                                 |X2
e|-----------------------------| |
B|-----------------------------| |
G|------2----2--------4----4---| |
D|-----------------------------| |
A|-----------------------------| |
E|--2----2--------3----3-------| /

An alternative to 
e|-----------------------------|
B|-----------------------------|
G|--------8------------9----8--|
D|-----------------------------|
A|-----------------7-----------|
E|--7----------7---------------|

Is
e|-----------------------------|
B|-----------------------------|
G|--------8----------9--8h9p8--| Not how they play it, but I think it sounds
D|-----------------------------| Better
A|-----------------7-----------|
E|--7----------7---------------|