Tuning: You can use either
(EADGBe) or (DGCFAD)
Both work in my opinion but D sounds better to me

Main Riff
-----------------------------------
-----------------------------------
------------------------------5----
-4-4-4-4-4--4--4-4-4--4--4-4--5----
-4-4-4-4-4--4--4-4-4--4--4-4--3----
-2-2-2-2-2--2--2-2-2--2--2-2--3----
 . . . . .  .  . . .     . .

Other riff
----------------------------------
----------------------------------
-------------------------3--2-----
-44--44--44--44--33--33--3--2-----
-44--44--44--44--33--33--1--0-----
-22--22--22--22--11--11-----------
 ..  ..  ..  ..  ..  ..

Hope this works better than those other ones out there!!!