where is the water pump located on a lumina sedan. and how do i replace it?

Dear DP0012--  The water pump on your 1993 Chevrolet Lumina is bolted on to the engine on the passenger side of the car.  For a look at the task you are facing, go to the following site--  http://autozone.com/servlet/UiBroker?ForwardPage=/az/cds/en_us/0900823d/80/0e/cb/0a/0900823d800ecb0a.jsp.   Good luck from Bovan.