Very beginning, before it goes into
the main riff:
e|----------|
B|----------|
G|---2--2---|
D|--0----0--|
A|----------|
E|----------|

Here's how the riff is played at first:
e|-------------------|
B|-------------------|
G|------------2--2---|
D|------0----0----0--|  x2
A|--2--2-------------|
E|-------------------|

And then this is the one played for the rest:
e|---------------------|
B|---------------------|
G|--------------2--2---|
D|------0--2---0----0--| then just play this
A|--2--2----0----------| a bunch.
E|---------------------|

Now, skipping to the end of the song,
literally the very end.
e|-------------------|
B|-------------------|
G|-------0-0--2/4-0--|
D|--0-0--2-2------2--|
A|--2-2--------------|
E|-------------------|
Again, just listen for the timing.