how to rewind spring for the z axis on a j head?

Hi everyone,

First off, I am an idioit. I volunteered my own time to rebuild a j head on a mill out of a combination of curiosity and stupidity.

That being said, I pulled apart the head and discovered the z axis spring was sprung. What is the proper procedure for rewinding the spring? If you can direct me to the thread or explain how to do so I would appreciate it.

Thank you