This guitar supports the Main Guitar (which you should look at first). Guitar 2 plays many of the same riffs, but there are some differences (highlighted below).
We're in Drop D Tuning: Low D : A : D : G : B : E
If you are in standard tuning, just play the middle D string (open) and tune down your Low E string (2 frets worth) to match it.
Intro - Before joining in with the main riff, Guitar 2 starts by playing powerchords.
Main Riff - Exactly the same as the Main Guitar apart from one thing. Very occasionally he plays a little harmony for this lick.
Second Riff - Same as the main Guitar except for this slide / note.
Third Riff - Played exactly the same way as the main guitar, except different notes are used, providing a harmony.
Lead Melody Backing - Start with a pickslide (scrape the edge of your pick down the length of 2 strings). Then play a simple powerchord sequence while the main guitar plays the main lead melody. Halfway through the lead melody Guitar 2 comes in with this lead harmony.
Pre-Solo Riff - Same as the main guitar.
Solo Backing - Just play the main riff while the main guitar does the solo.