You don't. That's the point of developing such a thing.

My point being: Even if you "just" do it like a tinkerer it ain't as easy as it may look. It takes a lot of blood, sweat and tears.

And the answer especially ain't : I know how because i read something somebody wrote somewhere on the internet or made a video about, i saw.

The density of the internet keeps on growing, no matter what. I somewhat doubted that a bit but less and less as time keeps on ticking.