I used the tab that's allready here, but it didn't sound accurate. So i tried some 
because the progression suggested seemed as a good base.
It finally came out it was good, but the tone was wrong, it actually is one full tone downwards.

So the thing is like this, the whole song goes with Gm - C7 with the main riff like 
[standard tunning, or capo on 3rd fret using Em - A7] Enjoy!

Riff 1
e--------------|
b--------------|
g-5^7--5-3-5---|
d------------5-|
a--------------|
e--------------|

After the chorus:
Riff 2
e-------------------|
b-5----6-----8------|
g-7^9--8^10--10^12--|
d-------------------|
a-------------------|
e-------------------|


--Tabbed by Tomás Anello. Buenos Aires, Argentina.--