Where is Fred and George's shop.?

In the girls bathroom (it is not used) on the sixth floor.

On the 6th floor. Then go through the door. Then the door that says its their shop.

Its in the girls bathroom in the 6th floor(ancient runes).then you will notice a door,go through that door.there will be books also.kill those books and then if you notice some water in that room use hermione to freeze it.then drag it to the skelon glass thingy and clim and then open the chest.and then in that room there will be a door names disgused (Fred and George)or something like that.then you will find them.go to a book named somewhat like:Chapter 1(at the end of the sentence).i cant remember the starting lol!then they will give you the statue list.and tranfiguration spell.use that spell as directed.last but not the least.Hermione's Statue list:
When you try to read a page from the Defence Book from Fred and George's Shop, (with Hermione), they will assign you a challenge to find nine statues just to read the book. Here's where they are.

Bridget Wenlock - Outside the door to the Fat Lady's Corridor, 7th Floor.

Gondoline Oliphant - In the Draconifors Passageway in the Study Room, 4th Floor.

Hengist of Woodcroft - Near the door to the Hospital Wing, 4th Floor.

Glanmore Peakes - Near the doot to the Glanmore Peakes Corridor, 6th Floor.

Beaumont Marjoribanks - In the History of Magic Classroom, 4th Floor.

Gunhilda of Gorsemoor - In the Gunhilda of Gorsemoor Corridor, 3rd Floor.

Gregory the Smarmy - In the 1st Floor Corridor.

Jocunda Sykes - Near the entrance to the Dungeons, Entrance Hall.

Hooky the House-Elf - In the door next to the Potions Classroom Door, Dungeons.

Hope I have helped:-)