I doubt that the water pump would have survived for 180k miles. It probably got replaced a long time ago, with a plastic once. Is the plastic orange or black? The black ones are made of a new composite material that is not really plastic -- it is actually the best water pump available for your car.
The pump was probably stuck because the engine had overheated and probably melted the gasket.
And yes, working on your car is ust a matter of doing some research beforehand, getting a hold of a few tools, being patient, and jumping right into it.