9Ball, are you actually curious whether anyone has replaced their water heater? Or, is the question really:
"How do I connect the water heater hoses to my engine so the engine heats the water"?
Unfortunately, as we can see, the question was interpretted as the physical installation of the device rather than how to connect it. Are we talking freshwater plumbing, electrical, alternative heating?
It depends on whether your engine is freshwaer or raw water cooled. Mine come off of the heat exchanger, however I never reconnected them when i repowered.