So, no-one has tabbed this incredible finale to "Holy Fire" - But as I plan to make a 
Youtube Cover at www.youtube.com/JBiddlecombe I shall try to tab by ear

The Chords are fairly straightforward

Chords for the first half -

Em  A   Bm   Bm

Then when the Organ is solo and get's loud -

Em  D   G    G    until the end of the song

The Intro to the song uses harmonics, muting, and a delay pedal

   Em                A                  Bm               Bm
e--------------------------------------------------------------------------|
B-----5h--------5h-------5h-------5h--------5h------5h-7h----5h------5h----|
G-----------------5h----------------12h--------------------------------7h--|
D--0------0--0-------0-------0--0--------0------0--0------0------0--0------|
A--------------------------------------------------------------------------|
E--------------------------------------------------------------------------|

So, you can play around with it, especially when you play Yannis' part up higher on the guitar.

I recommend playing around in the E scale -

e------------|
B-12-15-17---|         Basically, stick roughly to this plan, stick on a
G------------|         great deal of delay, and get those organ sounds out //
D------------|
A------------|
E------------|