I am assuming you have a supercharged engine in your 1996 Oldsmobile 88. The non-supercharged engine dose not require removal of the power steering pump in order to replace the water pump. There are three 13mm head bolts that secure the power steering pump to its mounting bracket. These bolts are accessed through the holes in the power steering pump pulley. The engine mount at the front of the engine should be removed before trying to remove the power steering pump.
I'm not the same guy that asked the question, but I've run into the same problem he had when trying to replace the water pump. You're wrong about the non-supercharged engine. Mine isn't supercharged and the rear-most bolt for the water pump is half covered by the pulley on the power steering pump. Even if I could get a wrench on it, I wouldn't be able to unscrew it all the way or pull it out because of the pulley.
But your answer to him did answer my question - I HOPE. Your answer led me to think that all three bolts holding the power steering pump are in the front and accessible through the holes in the pulley. My really old Haynes manual covers all models from 1985, and the photos show the power steering pump at the top of the engine, instead of behind it as it is in the 1996. Thanks for your answer for that info.