If I remember correctly I think you down tune 2.5 steps
Riff 1

|------------------------------|end of riff 1
|------------------------------|
|------------------------------|
|-2-2--2--2-2--2-5-7--7-8-3--3-| x3
|-2-2--2--2-2--2-5-7--7-8-3--3-|
|-0-0--0--0-0--0-3-5--5-6-1--1-|
Gurgle
 Riff 1a
|---------------|end of riff 1a
|---------------|
|---------------|
|-5-7--7-8-3--3-|x1
|-5-7--7-8-3--3-|
|-3-5--5-6-1--1-|
  . .  . . .  .
Riff 1 x8 On the forth and eight time around palm mute the last six notes of

 Riff 2
|----------------------------------------------------------------------------------|
|----------------------------------------------------------------------------------|
|----------------------------------------------------------------------------------|
|--------------------------------------------------------------------5-7--7-8-3--3-|x2
|--------2"-----3"-----------2"-----1"-----------2"-----3"-----------5-7--7-8-3--3-|
|-0"-------3"-2"------0"-------3"-2"------0"-------3"-2"------0"-----3-5--5-6-1--1-|

Riff 1 x8 On the forth and eight time around palm mute the last six notes of
Riff 2 x2
 
 Riff 3
|------------------------------------------------|
|------------------------------------------------|
|------------------------------------------------|
|-------------------------------------5--7--5--2-|
|------------------------------5*-----5--7--5--2-|
|-7~---6~---5~---0--3~--0--6~-----5~--3--5--3--0-|

 Riff 3 cont.
|-----------------------------------------------|end of riff 3
|-----------------------------------------------|
|-----------------------------------------------|
|------------------------------------5--7--5--2-|
|----------------------------5*------5--7--5--2-|
|-7~--0-6~--0-5~--0-3~--0-6~-----5~--3--5--3--0-|
Riff 3 behind solo

|---------------|
|---------------|
|---------------|x3 (third time palm muted)
|-5-7--7-8-3--3-|
|-5-7--7-8-3--3-|
|-3-5--5-6-1--1-|

end with
|-----------|
|-----------|
|-----------|
|-2-2--2--2-|
|-2-2--2--2-|
|-0-0--0--0-|
  . .  .  .