It's just one of the bonus tracks of her album "The Best Damn Thing"

Title: I can do Better (Acoustic)
Artist: Avril Lavigne
Album: The Best Damn Thing

Tuning: Standard
Legend: x-dead note

Intro:
Guitar 1

e|-x-x-x-x-x-x-x-x-x-x-x-------------------------------|
B|-x-x-x-x-x-x-x-x-x-x-x-------------------------------|
G|-x-x-x-x-x-x-x-x-x-x-x-------------------------------|
D|-x-x-x-x-x-x-x-x-x-x-x-------------------------------|
A|-x-x-x-x-x-x-x-x-x-x-x-------------------------------|
E|-x-x-x-x-x-x-x-x-x-x-x-------------------------------|
(continuation after the dead notes)
e|-----------------------------------------------------|
B|-----------------------------------------------------|
G|-5-5-5-5-5-5-----------------------------------------|
D|-5-5-5-5-5-5-5-5-5-5-5-5-3-3-3-3-3-3-----------------|  (Two Times)
A|-3-3-3-3-3-3-5-5-5-5-5-5-3-3-3-3-3-3-----------------|
E|-------------3-3-3-3-3-3-1-1-1-1-1-1-----------------|
Guitar 2

e|-----------------------x-x-x-x-x-x-x-x-x-x-x-x-x-x-x-|
B|-----------------------x-x-x-x-x-x-x-x-x-x-x-x-x-x-x-|
G|-----------------------x-x-x-x-x-x-x-x-x-x-x-x-x-x-x-|
D|-----------------------x-x-x-x-x-x-x-x-x-x-x-x-x-x-x-|
A|-----------------------x-x-x-x-x-x-x-x-x-x-x-x-x-x-x-|
E|-----------------------x-x-x-x-x-x-x-x-x-x-x-x-x-x-x-|
(continuation of guitar 2)
e|---------------------------------------------------------------|
B|---------------------------------------------------------------|
G|-5-5-5-5-5-5-------------------------5-5-5-5-/9-\7-\5----------|
D|-5-5-5-5-5-5-5-5-5-5-5-5-3-3-3-3-3-3-5-5-5-5-/9-\7-\5----------|  
A|-3-3-3-3-3-3-5-5-5-5-5-5-3-3-3-3-3-3-3-3-3-3-/7-\5-\3----------|
E|-------------3-3-3-3-3-3-1-1-1-1-1-1---------------------------|

e|------------------|
B|------------------|
G|------------------|
D|-5-5-5-5-3-3-3-3--|
A|-5-5-5-5-3-3-3-3--|
E|-3-3-5-3-1-1-1-1--|

Verse

Both guitar 1 and 2

e|-----------------------------------------------------|
B|-----------------------------------------------------|
G|-5-5-5-5-5-5-----------------------------------------|
D|-5-5-5-5-5-5-5-5-5-5-5-5-3-3-3-3-3-3-----------------|  (four Times)
A|-3-3-3-3-3-3-5-5-5-5-5-5-3-3-3-3-3-3-----------------|
E|-------------3-3-3-3-3-3-1-1-1-1-1-1-----------------|

Refrain

Both guitar 1 and two

e|-------------------------------------------------------|
B|-------------------------------------------------------|
G|-------------------------------------------------------|
D|-7-7-x-x-x-x-x-x-x-x-3-3-x-x-x-x-x-x-x-x-x-------------|  (two rimes)
A|-7-7-x-x-x-x-x-x-x-x-3-3-x-x-x-x-x-x-x-x-x-------------|
E|-5-5-x-x-x-x-x-x-x-x-1-1-x-x-x-x-x-x-x-x-x-------------|

Chorus

guitar 1

e|-----------------------------------------------------|
B|-----------------------------------------------------|
G|-5-5-5-5-5-5-----------------------------------------|
D|-5-5-5-5-5-5-5-5-5-5-5-5-3-3-3-3-3-3-----------------|  (four times)
A|-3-3-3-3-3-3-5-5-5-5-5-5-3-3-3-3-3-3-----------------|
E|-------------3-3-3-3-3-3-1-1-1-1-1-1-----------------|

Guitar 2

e|-12-13-15-13--| 
B|--------------|
G|--------------|   (repeat it until the chorus is done)
D|--------------|
A|--------------|
E---------------|


Repeat it the verse and the refrain and the chorus
nothing changes until the bridge

Bridge

both guitar one and two

In fact i can't sound how many dead notes are there in the bridge

e|------------------------------------------|
B|------------------------------------------|
G|-5-5-x-x-x-x-x----------------------------|
D|-5-5-x-x-x-x-x----------------------------|
A|-3-3-x-x-x-x-x----------------------------| 
E|------------------------------------------|

changes in "hey hey"

e|------------------------------------------|
B|------------------------------------------|
G|-5-5-5-5-5-5-5----------------------------|
D|-5-5-5-5-5-5-5----------------------------|
A|-3-3-3-3-3-3-3----------------------------| 
E|------------------------------------------|

Go back to chorus
but guitar 1 changes in the second time of the chorus


e|---------------------------|
B|---------------------------|
G|-5-5-5-5-/9-\7-\5----------|
D|-5-5-5-5-/9-\7-\5----------|  
A|-3-3-3-3-/7-\5-\3----------|
E|---------------------------|

e|---------------------------|
B|---------------------------|
G|---------------------------|
D|-5-5-5-5-7-7-7-7-3-3-3-3---|
A|-5-5-5-5-7-7-7-7-3-3-3-3---|
E|-3-3-3-3-5-5-5-5-1-1-1-1---|

goes back to the chorus again

outro

Guitar 1 and guitar 2

e|---------|
B|---------|
G|-5~------|
D|-5~------|
A|-3~------|
E|---------|

I believe that there is still guitar 3 but It's just like guitar 1... 
but theres no changes like the other two guitars....

hope you'll enjoy!!!