I've never messed around with butchering an ESC before.
The red wire is positive.
The brown wire is negative.
The orange wire is the signal.
You will also need a variable resistor. Like a volume control or trigger type control.
The best thing is to plug it up properly with a receiver. if you are not good with electronics you will burn this system up. What you want is obtainable but I don't know that using that stuff is the way to go for you. Why not just use a motor with a vatriable resistor. That way you don't damage the ESC you have. Good luck with your project.