How to deal with Inferi

To the left of the wall there is a student with a ladle looking object above his head.

Go down the stairs and look for a student carrying the ladle. Zap him 3-4 times with your attack spell and he will drop it. Bring the item back to the first student and the wall will explode.

After donning your invisibility cloak and sneaking across the screen you will encounter a pumpkin which can be levitated.

On the Wii this is accomplished with Z on the nunchuck. To get the pumpkin rotating you press in a direction. If you press it any direction but straight to the left you will get the weak throws. Pressing left will magic-bullet-targetting-system onto Death and you can bean him.

I'm advised that this problem on the Xbox involves using the B button, not the X button, to pick up the pumpkin in the first place.