How to edit Assembly-Csharp

Hello.

I was just wondering how the hack from Kunii is made.
He edited the Assembly-Csharp in some way, but how do i do that?

Any help or resources?

iirc, it's patched

when the game updates you have to do it all over again

I have the .Net Reflector atm. It works great, but the variable names are just some symbols. Ideas how to fix that?

Hack is fixed not working..