How do I replace a non-removable hose connection vacuum breaker?
You do know the meaning of non-removable, right? That being said, you'll need to replace the spigot. Those fittings have a brake-away threading system that allows you to tighten them for installation but breaks away the sleeve from the threads if you try to turn it counterclockwise. Something like the safety caps on pill bottles. Now, I have removed them with a Dremel drill with a cutoff wheel and carefully cut the breaker off of the spigot but it was a slow process so I wouldn't damage the threads on the spigot. the next time I came across one that had to be removed, i just replaced the spigot and added a new breaker.