Well i think this is the most correct way to play this song


    RIFF "A"               RIFF "B"                      RIFF "C"
e|--------0-3-2-0--    ---------5-8-7-5--           --------7-10-9-7--|
B|-----1/2--------- x2 -----6/7----------           -----8/9----------|
G|-2-2------------2    -7-7-------------7  RIFF "A" -9-9------------9-|
D|-----------------    ------------------           ------------------|
A|-----------------    ------------------   Again   ------------------|
E|-----------------    ------------------           ------------------|

Well that's the main riff on the first part.

Then, the part after that Drums bridge when they sing "Yes we're goin to the
party, party" it's like this:

e|-------------------------|
B|-------------------------|
G|-------------------------|
D|-7-7-7-7-7-7-7-7-7-7-7-7-|
A|-7-7-7-7-7-7-7-7-7-7-7-7-|
E|-5-5-5-5-5-5-5-5-5-5-5-5-|
   Yes we're going to the party, party

Yes, that's like it is going.
Then, th part of "I would like to dance, biiiirthday"

e|-----------------------------    -------------------------------------|
B|-----------------------------    -------------------------------------|
G|-----------------------------    -------------------------------------|
D|-----2-2-4-4-5-5-3-3-2-2-0-0- x2 -----2-2-3-3-4-4-5-5-6-6-7-7-8-8-9-9-|
A|-3-3-------------------------    -3-3---------------------------------|
E|-----------------------------    -------------------------------------|
  I would like to dance                      DAAAAANCE
                  "Birthday"

e|-12-    -13-|
B|-13-    -12-|
G|-12- x6 -12-| x6
D|----    ----|
A|----    ----|
E|----    ----|
This is the piano fill

Then there are the main riffs playing

And this is the little solo
e|-------------------------------------8-10b-8-10-8------|
B|---5-8-8b-5------------------5-8-10---------------10-8-|
G|------------7-5----------------------------------------|
D|-7--------------7-5-------7----------------------------|
A|-------------------------------------------------------|
E|-------------------------------------------------------|

And at the end there's the main riff and it ends :) THANKS FOR SEE THIS TAB