How to unlock luigi
First as Mario go through the wooden door in side the castle on the bottom. You will see a big boo fly away through another wooden door, follow it. Go in the door and there will be a lot of small boo's, there will also be a big one. Punch it and a cage will appear go next to it and you will go in. You will have to get the first star to unlock the stairs to go up to the second floor. After you have unlocked the stairs, climb them and go into the room with the books. You will have had to unlock the red ! Boxes. Jump up and collect the power flower to inflate with air and press B until you see a platform with a door. After you have deflated, go in the door. You will see a painting with Luigi on it, jump into it. You will hear laughter, follow the laughter. You will come to a room with a big mirror, stare in the mirror and your reflection will turn into Luigi, then you will see a big boo. Kill the boo by looking at it's reflection in the big mirror. Then a key with a Luigi hat will appear. Grab it and then go to the room with all the doors and unlock the door with the L on it and you will turn into Luigi! Hope I helped, thanks for reading!
Added by: toralei150 Aug 5th 2012, ID#17277