How can I change the self ilumshader its emission value on a material from a script?

I want to change the value for the emission from a script, but I am not sure how I can acces that variable and I can’t open the buildt in shader.

The sources of all built-in shaders can be downloaded from here. From these you can find the names of all uniforms (parameters). I don’t think any have a straight color for _Illum, only textures, but it’s pretty easy to add if you need it (and for that, start with these sources).

Got it,

var emission = 100;
renderer.material.SetFloat( "_EmissionLM", emission );