How do you get reducto in Lego Harry Potter for Wii?

Answer 1

First you must learn Reducto in the Room Of Requirement.

Once you have learnt it, you aim at an object and hold the Square button for 2-3 Seconds.

Answer 2

if its on ps2 then move the right toggle round anticlockwise.

Answer 3

In Harry's fourth year at Hogwarts you go to "Mad-Eye" Moody's classroom. Which is where you learned your Patronus Charm or a little ways down from Remus Lupin's classroom.