What is needed to learn to make mecha's

I now know this is becoming possible to make, Japan has made a moving one with just two legs and a pilot on top (http://www.youtube.com/watch?v=oVwbUljGs3g).

So I would like to know what I will need to make a fully tall made mecha, I know I need to learn engineering, what else?

Robotics, electrical engineering, physics? There's a lot of different peoples with different diciples that go into projects like that.

A, A or B in Dt and art
And trust in ur self
and suport