Coolant leak

I have a 1990 Pontiac Sunbird conv w/ 2.0L engine and 128000 miles. When the engine gets to full temperature (1/2 way up the gauge and fan is on) it leaks coolant out the bottom below the area of the water pump, one might even say gushes coolant out the bottom. When the engine is cool and up until the gauge reaches 1/4 the leak is non-existant or very slow. It seems that the fuller the coolant the faster the leak, after some of the coolant is gone the leak slows down, but will eventually leak enough to cause the engine to overheat. The leak appears to be coming from the area of the water pump or the two hoses that connect to the engine below the intake manifold and behind the power steering pump. I am looking to remove the Alternator and Power steering pump in hopes of replacing those hoses. I checked a Chilton's manual and can not find any information on replacing those hoses. How big a job is this for an amateur mechanic? How much more teardown is required to access the Water pump? I am wondering if I should just tear down and replace the water pump and the hoses together. Would a cracked block tend to leak more when the engine was cool vs hot? ?