Ok...the intro is played by bass and guitar the same, but the bass plays

---             ---|
---             ---|
---             -0-|
-5-- instead of ---|

let's go...

------------------------------------------------------|
------------------------------------------------------|
------------5-----------------------------5---7--5--2-|
-7-7-7-7-7--3---7-7-7-7-7--5---7-7-7-7-7--5---7--5--2-|
-7-7-7-7-7--3---7-7-7-7-7--5---7-7-7-7-7--3---5--3--0-|
-5-5-5-5-5------5-5-5-5-5--3---5-5-5-5-5--------------|

this is the main riff

in the chorus are power chords used too, but i don't know which, i suppose Gonzo uses 
same like in the main riff, try it and mix 'em

Have fun!

Seatiger