Just how do the workers establish a democratic workplace within and under a totalitarian ownership?

Were all the workers willing to give the attempt a shot , and in the current atmosphere that is largely anti-union this is problematic,  what is to prevent the ownership from firing the leaders of such a movement and replacing them with more compliant workers and thereby setting the example of economic knee-capping for the rest of those who might even consider democratizing the workplace?

That private ownership and the right of the owners to hire and fire is backed by the police, Sattes police, National Guard and on up as high as necessary .

How is this overcome?