Frankie is right. Look in Chiltons. Then consider paying a shop to do it. Anybody might take it apart, but you want it to get put back together correctly.
How to change a heater core on a 1993 grand marques?
Your best bet is to get a repair manual (about $20.00) at your auto parts store. It has step-by-step instuctions on how to do about any repair you need to do. The heater core is usually under the dash on the passenger side and a lot of times you have to remove part of the dash to get to it.
They're not fun so good luck
