E|------|--|
B|------|--|
G|---2--|--|
D|---4--|--|
A|---3--|--|
E|------|--|
   1st    2nd fret

(2nd finger = your middle finger, 1st = your index finger, etc.)
The idea is that you use lift off and hammer on your 2nd finger to rock 
between Em, E and Esus4 in a riff like this (switching to tab notation)

     Em   Esus4  E
       H         H         H
E|---0----0----0---0--0--0------------------------|
B|---0----0----0---0--0--0------------------------|
G|---0-1--2----0-1-2--2--0-1----------------------|
D|---2----2----2---2--2--2------------------------|
A|---2----2----2---2--2--2------------------------|
E|-0-----------------------------------------------|
     \----+    \--------------+

The Em is played for about 8th-note duration; the overall chord is an E and
the G (open G string) of the Em and the sus4 are nothing more than passing 
tones.

Trey does some other stuff here, mostly noodling around on these chords,
that I'm not going to write out, but listen to any recording and he'll do
something different yet interesting; I'll just show the underlying chords
below.

E riff
I come from atop the mountain baby
Where the people come to pray
A
I come from atop the mountain baby
                         E
Where the people come to pray
B
Ain't no truth in action
G          A         E
Less you believe any way

(Same chords)
I was riding down the road one day
Someone hit a possum
I was riding down the road one day
Someone hit a possum
The road was his end
His end was the road
So they say

Chorus:
     E (hold 4 bars) E (riff)
Whoa possum...       possum
     A (hold 4 bars) E (riff)
Whoa possum...       possum
     B
Whoa possum
G    A          E
Your end is the road

Solo:

         E chord

      2         |     |           |
     /
E|-15---|-12----------------------------------|
B|------|----15-14-13-12----------------------|
G|------|----------------14-13-12-13----------|
D|------|----------------------------14-12----|
A|------|----------------------------------14-|
E|------|-------------------------------------|


               |        |           |

E|-------------------------------------|
B|-------------------------------------|
G|-------------------------------------|
D|-14----------12----------------------|
A|----14-13-14----14----13-12----------|
E|-------------------12-------15-12-12-|
                                 \--/

         |       |       |               |       |       |

E|-----------------------------|---------------------------------|
B|-----------------------------|---------------------------------|
G|-----------------------------|-----------------------0-1-------|
D|-----2-------0---------------|-------------2---0-1-2-----2-0-1-|
A|-0-2---2-1-2---2-1-0---------|-0-1---0-1-2---2-----------------|
E|---------------------3-0-0-3-|-----3---------------------------|

   A chord

           |       |       |                |        |           |
         /S        /S    /S           /S          /S
E|----------------------------------|--------------------------------|
B|---2-----3---5-----7-----8----9---|----10-10-------10----12----10--|
G|----------------------------------|--------------------------------|
D|-2---2-4---5---5-7---7-9---10---10|-11-------10-11----12----11---12|
A|----------------------------------|--------------------------------|
E|----------------------------------|--------------------------------|
   \---/     \---/ \---/


   E chord

              |           |        |
   /S
E|----12---------------------------------------|
B|------15-14-13-12----------------------------|
G|-13---------------14-13-12-14-12-14-14-12----|
D|------------------------------------------14-|
A|---------------------------------------------|
E|---------------------------------------------|


                           B7 Chord

           |        |  |         |       |       |

E|-----------------------|------------------------------|
B|-----------------------|------------------------------|
G|-14--12--11--10--------|-----------6-----6-7-8------9-|
D|---14--14--12--12-14---|---7-----7-----7-------9------|
A|-----------------------|-9---6-9-----9----------------|
E|-----------------------|------------------------------|



   G chord         A chord                  E chord
                 |   2        |              2
    3  3  3         /                       /------
E|----------------------------------------|-----|
B|-----------------12-10------------------|-----|
G|-11-12-11-9-11-9-------11-9-------------|-----|
D|----------------------------10-11-10-11-|-7---|
A|----------------------------------------|-----|
E|----------------------------------------|-----|



                          E chord (2nd time through progression)
   |  |   |  2   | 2               |          |         |
E|--------+| /     /
E|--------14--12-17--15-|-------------------------------------12---|
B|----------------------|-17--16-15---15---------------------------|
G|----------------------|---16-----16---16-15-14---14---12-13----13|
D|----------------------|------------------------14--14------------|
A|----------------------|------------------------------------------|
E|----------------------|------------------------------------------|

        2        |          |  |
       /      P                 /S
E|--------------------------------------|
B|-14-14-(14)-12-14-12------------------|
G|---------------------12-13-------9----|
D|--------------------------14--11---11-|
A|--------------------------------------|
E|--------------------------------------|
   \--/\--/

         |        |          |                 |        |
                  3  3  3                               /S
E|------------------------------------|-------------------12--12---|
B|-12-11-10---------------------------|----------------------------|
G|---9--9--9-11-9-12-11-9-11-9--------|--------11--9-11-13--13---5-|
D|-----------------------------11-9---| 11--9-11--11----------------|
A|----------------------------------11|--11------------------------|
E|------------------------------------|----------------------------|



   A chord
           |       |       |               |       |       |
   H
E|---5----------------------------|--------------------------------|
B|-----8-7-5----------------------|--------------------------------|
G|-6---------5-6------------------|--------------------------5-7-8-|
D|---------------7-5---7-------5--|--------------------5-6-7-------|
A|-------------------7---7-6-7----|-7--6-5-------5-6-7-------------|
E|--------------------------------|--------8-5-8-------------------|



   E chord
           |       |      |                 |       |   |
     3 3 3                                            ~
E|--------------------------------|-----------------------|
B|--------------------------------|-----------------------|
G|-9-9-8-7---7--------------------|-----------------------|
D|---------9---9-8-7----------6---|-6-7-8-9-6---------6---|
A|-------------------10-7-7-----7-|-----------7-----7---7-|
E|--------------------------------|-------------9-7-------|


   B7 chord
         |       |       |

E|-------------------------|
B|-------------------------|
G|-----------6---7-8-7-8---|
D|---7-----7-------------9-|
A|-9---6-9-----9-----------|
E|-------------------------|

(Same chords as earler verse

I was riding down the road one day
Someone hit a possum
I was riding down the road one day
Someone hit a possum
The road was his end
His end was the road
So they say

chorus:

     E (hold 8 bars) E (riff)
Whoa possum...       possum
     A (hold 8 bars) E (riff)
Whoa possum...       possum
     B      G    A          E
Whoa possum your end is the road
     B      G    A          E
Whoa possum your end is the road