you can't.
Look in the mirror. Your reflection should change to Luigi. Defeat King Boo and Luigi is yours.
Mario must enter the door with no number or star and follow King Boo. Using the power floor Mario must float up to the platform to confront King Boo. Once he defeats King Boo using the reflection in the mirror he will get the Luigi key. This key unlocks Luigi as a playable character.
There are two "mirrors", the one by Snowman's Land and the one in the Boo battle to get the Luigi Key. The Snowman's Land mirror can be passed through by getting the Power Flower as Luigi and going through the mirror. There is also a Secret Star through the reflected exit door. The mirror in the boo battle reflects King Boo's location (his shadow is also on the floor).
If you mean the mirror room where you unlock Luigi (in Big Boo's Haunt) when you fall to the room, just go forward and touch the mirror with Mario, then wait. You'll have to battle King Boo to unlock him.
to get luigi you have to go to boo's mansion with mario. near the place you fight boo, there will be a luigi picthure.hop in it to fight king boo and get the luigi key. to get wario you have to have luigi.you need a room with mirrors. there will be power flowers. they will make luigi invisable.there will be a wario painting.hop in it to fight chief chilly! that is how you unlock wario and luigi. P.S.go though the mirror door to get a star.
same
go to the courtyard hop on ghosts until you find the one with the cage in it and then hop on it do stages in it until you must go into attic of house in attic: go and hop through luigi painting in painting:go through maze/obstacle course jump down hole at the end of the course to defeat king boo: go stand in front of mirror until mario's reflection looks like luigi to see king boo look in mirror make your reflection jump on king boo to hurt him, repeat three times to defeat Note:king boo switches sides after you hurt him. when he happens be on your side dont use mirror
Hmmmm. If you are talking about Super Mario 64 DSthen i can help you if you ain`t......well someone will have to edit this answer. You are asking `HOW can you beat king boo?` right? then i won`t have to go through all the things on how to get to the Luigi painting and all that stuff. When the battle starts after King Boo talks to you, DONT FACE HIM. In fact, face the opposite way until he comes close enough for you to backflip and stump. backflip and stump then he will teleport, i say, TELEPORT THROUGH the mirror. You cant see him but you can see him across the mirror. Now you can hit him the second time in either of these ways: A: watch Luigi in the mirror and control him like you control mario. repeat the first step above to hit him again. B: there will still be the shadow of King Boooutside the mirror. All you have to do is pretend that the Shadow is King Boo and backflip and stump the Shadow. Finally, King Boo comes back outside the mirror. You just have to repeat the first step above to defeat him and GAIN LUIGI`S KEY AND UNLOCK LUIGI AND DO ALL SORTS OF THINGS!!!!! MUAHAHAHAHAHAHAHAHAHAHAHAHAHAHAHAHAHAHAHAHAHAHAHAHA
King Boo is bowser
Go into Boo's Mansion,go to the room with a tipping floor,stand on the ? block,backflip in the direction of the door,go into the door and you will see a picture of Luigi(the picture in the mirror room is FAKE!!!!!)You will have to follow the sound of King Boo's maniecal laugh.Once you make it,drop into the hole on the top and go up to the mirror and walk around it for a few.Then you will see an illusion image of Luigi and King Boo will appear.He doesn't do a lot of attacks,but he will try to trick you by becoming invisible to the mirror and actual world.Just watch where he and you are(another illusion is that when you see Luigi in the mirror,it actually marks where you are.)When you get the key just go to where you get Mario and BAM!!!!!You get the Man in Green!
you mean on sm64ds? get to the mirror room and stand in front of the giant mirror until king boo shows up. Don't get too close just stand a little bit away from the mirror.
you need to go into a room with Mario with two pedistals with flowers on them. jump into the flower and you will be invisable. go through the mirror and on the right side jump into the luigi painting. go throught the level and then you look into a certain mirror in the level very closely you will turn into luigi on the mirror side then youwill battle king boo. after you ground pound on him three times you will get the luigi key. Hope i helped!!!