Use reducto
A door in the front next to the stairs.
you go to the main section of Hogwarts where there are two flights of stairs and you go up the left on and that Door is the library. *please note you need a certain spell to open the library*
Go to the charms room (the dark one). There is a trap door with a question mark on it. You might have to do something to unlock the trap door either in this room or the room next door. Enter the trap door, go right avoiding the traps and you will get to it. You will need dark magic to get it, though.
The bathroom door isn't available, it's just there to add more detail to the scenery of Lego Harry Potter.
Mrs.Figg
If it's got a metal Lock on it, then you must wait until year 4, but if there's red sparkles, you will have to use polyjuice potion to turn into someone like Tom Riddle or a death eater.
http://cheats.freeola.com/playstation_i/harry-potter-and-the-chamber-of-secrets_4532.html this will help you btw you and me bouth man i was qureas for years :) XD
go to the door that leads to London train station and press contine story
When you pass the door to the area with the second prefect, you need to turn right to the hallway with the portrait - talk to it and it will distract the prefect.
if you are talking about the port when you are in the dark in year 3 you go find then one in a chest in the shkret door and the other in the sekeret door next to it
Flagrante
It is in the same area as the potions room. It is the door near the earmuff cabinet. You can find her character token in there.