Pontiac Repair: 97 Grand Am Heater, tin snips, rubber nipple

Question
I need to replace the heater core on my 97 Grand Am so I can sell it.  I plan on doing it myself, but would like some instruction, directions, and some idea of what I am getting myself into.  I restore old GTO's (66 and 67 mostly) so I am quite knowlegeable about cars, but know these newer ones can be more complicated.  Any guidance on how to do it and how hard it is (especially in comparison to the old GTOs) would be appreciated!

Answer
Hey Lauren:

Well I hope you like working on your back. If this car has a 4 cylinder it's easier under the hood than the V^ to get the hoses off. the core comes out from the inside of the car. you have to take the hush panels down on both sides of the dash. you have to remove the center console assembly. You can leave the shifter and parking brake in the car. there is an outer cover that the right and left side dash vents and floor vent are attached to it has maybe 3 screws on it take the vent hoses off that. then the bottom cover has to come off the heater box that is where the problem is. when you take the hoses off outside the car also pull the elbow off the a/c drain it's just a rubber nipple and pulls right off. back inside the car take the gas pedal off the fire wall it has 2 or 3 bolts and then take all the screws off that hold the bottom cover on there are maybe 8 or 10 of them and a couple of them are really hard to see. They are 7/32" or 5.5MM next roll the carpet back and if you can the liner under the carpet it helps in pulling that cover down. You have to pull it down and back at the same time it's real pain in the butt. that's it reverse the procedure to re assemble. when you pull of the cover be VERY CAREFUL you do not bend it too much or flex it it will BREAK. Before you put it back up there are a few cut outs in that cover where the heater pipes go through. Use a pair of tin snips or dykes and widen the holes a bit it makes it easier to re assemble and it will not hurt anything. Just do not cut them any deeper then they are already  the condensation from the A/C will leak into the car. and when you put it back up in there there is a little groove all the way around the heater box that this cover fits in if it's not in that groove the holes will not line up for the screws. Good luck :) even when you know what your doing this job sucks and it takes about 1 to 1.5 hours to do.