How do you get the key so you get to warios painting?

To get into wario's painting in the ''mirror room'' you need luigi to get luigi :
1. Get the level big boos haunt in the courtyard.
2.enter the level as mario
3.when you arrive go through the door and go up the steps directly in front of you.
3a.if the steps arent there clear level 1 then go into level 2 on big boos haunt.
4.go to the room right from the top of the steps.
5.once in the room go forward to the ? Box.HIT IT.
5a.if you don't have the ? Box solid ha ha you can't do it but if you have...
6.get the power flower and float upwards unit you see a ledge once above the ledge ground pound.
7.go throughthe door and you should see the picture of luigi go in the painting.
8.now look at your map there are 4 doors go to the top one by looking at the map.
9.keep looking at the map going to the top door.
10.you should get to long line of falling bricks run.
11.once at the other side get up and you should see a hole jump down.
12.face the mirror in first persons mode look into the mirror you should see mario reflection become luigis.
13.(unlucky)follow the shadow on mario side of the room jump and hit defeat king boo.
14.get luigi from his room and go to the mirror room power flowers should be there get it.
15.once invisible walk through the mirror now you can either go straight forward or you can jump into the painting (if you go straight forward to the door youll get a ......................STAR WOW)
Try figure warios level yourself I havent done it yet
CRASH WONDER SAYS''HOPE I HELP REMEMBER I'M NOT THE BEST''

Firstly, you need to get Luigi.

1. Go to the courtyard behind the castle, via close to the entrance to the basement by going through one of the wooden doors in the lobby as Mario.
2. Kill the boo which has the entrance to Big Boo's Haunt
3. Go into the mansion at big boo's haunt, then triple jump up to the second floor, the go to the door furthest right. 4. There will a ? Box in that room, hit it and grab the flower, the float your way up until you see a secret door above where you were. Go in.
5. There will be Luigi's painting. Go in.
6. To complete this area turn the sound up maximum, and listen for King boo's laugh. Go in the doors that lead to his voice.
7. Defeat King Boo by Backflipping then ground-pounding him 3 times.
8. Go and get Luigi, then go to the second floor, then go to the door on your right, this is the mirror room. Grab a flower on the pedestals and run into the mirror. Enter Wario's painting.
9. Complete the area until you get to Chief Chilly. Defeat him like how you would to a bully in Lethal Lava Land.
10. Repeat 9 three times.
11. Grab key then go get Wario.

EASY!