[A930Rocket]

I have several broken exhaust manifold studs on my 2001 F150 with the 5.4 and you can hear the exhaust leaks. I want to pull the manifolds and replace the studs, while keeping the carnage to a minimum. What's the best way? PB blaster soaking for several days and wrench the off by hand?

I've heard using an impact does well to remove the nut and prevent broken studs. Truth or rumor?