Drop tuning to Gb, Ab, Db, and Eb.

Riff One
Gb------------------------------------------------------------------------|
Db---7-7---6---5---5-3---2---1--------------------------------------------|
Ab------------------------------------------------------------------------|
Eb------------------------------------------------------------------------|

Riff Two
Gb------------------------------------------------------------------------|
Db-0-1---4-----0-1---4-----0-1---4-----0-1--------------------------------|
Ab---------1-----------1-----------1--------------------------------------|
Eb------------------------------------------------------------------------|

Riff Three
Gb------------------------------------------------------------------------|
Db--9--6/8--5---5-66-7--8-----3-------------------------------------------|
Ab------------------------------------------------------------------------|
Eb------------------------------------------------------------------------|

Listen to the song for the structure. (It's really easy to figure out)