Guys, could you tell me how to change the Shaders?

If shaders can run on your computer then you press /lws (shadername).inc
the avialabe shaders can be found in: My computer/local disc C/games/toribash/data/shader.

I want to add to OfPhailure's information:

The shader names ARE case sensitive so spell them character by character.

In other words, "Computer" and "computer" are two different words because the "C" is in uppercase and lowercase.