I'm on year 2 on ds. How do you beat the big snake on the tower?

Shoot the snakes tail with your wand and it will go into the tower thing, there are three little levitating platfoms in line with where the snakes tail just was. Go to the one furthest away from the statue and you will see that you will be able to jump to the middle of the Horizontal line of platforms (the only one you could levitate) make your way up to the top of the tower using those platforms (once you got on the middle/levitating one you can reach the ones further up) beware that the snake will come out of some of the holes a few times but remember to simply shoot at it with your wand. Once you get to the top of the statue/tower there is an object you either need to cast a spell like transfigure it or shoot it - I can't remember - then the sword of gryffindor appears in it's place. You need to levitate it and then that's it! The chamber of secrets is completed! You get a movie clip at the end and start prisoner of azkaban!! Good luck with this, I hope it makes sense and helps!