ok be patient! You also might want to try the latest mouth soap.
Before you can do anything, you must have beaten 1 bowser stage and pressed the red switch. i hope you know how to do that, cuz i don't feel like telling you.
To unlock luigi, become mario. Go to big boos haunt. If you have not gotten the star "go on a ghost hunt" you must do that first. go to the second floor. There is a room with a bookshelf and a trapdoor. avoiding the trapdoor, find the raised platform with the red box on it. Destroy the box, and a power flower will come out. get the power flower. press A repeatedly. you will see another platform with a door at the end. go on the platform, press Z, and go thru the door. you will see a portrait of luigi. You probably know what to do next. At this point you must have the sound on. You should be in a merry-go-round, hearing an annoying laughing. Follow the direction of the laughing through a few rooms. If you go the wrong way you will end up back in the merry-go-round. If you go the right way you will eventually end up in a room with a mirror. stand next to the mirror, and the King Boo (master of annoying laughter) will appear. This boss is relatively hard, but it helps if you notice the coins on the sides of the room. Defeat king boo, and not only will you have silenced this irksome, maniacal monarch, but you will have the key to Luigi's room.
To get Wario, you must have gotten Luigi and beaten the second Bowser course. Become Luigi. Go to the room that has the entrance to Snowman's Land. You will see a few power flowers. collect one, then run thru the mirrors. 🤔 once you are on the mirror side of the room, go thru the door at the far side. all that you will see is yourself, the door, an abyss of white, and a STAR! Go back into the mirror room, and find the portrait of wario.
at the end of the course you will fight Chief Chilly, a harder version of Big Bully who insults Luigi's moustache. Defeat him by knocking him into the ice water 3 times with well timed punches.
Hope this was helpful