You don't hit the threaded part of the taper you hit the subframe adjacent to the taper the resulting shock releases it ,if you run the nut so it is flush with the end of the thread and jack the car up so the weight of the car is on it (the nut giving a bigger footprint for the Jack)the upward force helps with the release, then if the nut spins after release just force the taper back in with a bar undo the nut and prise back out with the bar or prise and tap the subframe again and it will pop right out
