I just recently purchased a 68 RS and the heater core has started to leak. I have never worked on a Camaro (any year model). It looks to be a pretty tough job. How do I get to the bottom heater hose located at the firewall to remove it? Do I need to remove the A/C components above or remove the fender well or what?

Try from underneath the car, I used a long screwdriver while laying on my back under where I could see up to the clamp. Otherwise, leaning over the fender with small screwdriver or ratchet if its a nut type clamp and reachin blindly till you get it, but then when you reinstall the clamp, Id do it from under, much easier in my opinion.

make sure you drain the coolant first :p

My .02 cents worth and a little late, I was checking threads for my continually leaking thermostat seal and saw this one and as I have replaced my heater core for the second time I can give you some well seasoned advice..
1- You need to to remove outer fender to get to heater core clamps to re-re this part..remove outer connected to inner fender as they overlap and are a bugger and near impossible to miss this step and to succeed in this adventure.
2- Unbolt heater box nuts and bolts from firewall side as well as under dash removing glove box makes things more convenient.
3- When installing new heater core and if you require to bend snouts to fit through firewall you must remove heater box and flash test your new heater core before buttoning everything up..as I know this from personal experiece.If you tweak that soldered joint at all reflash,reflash..save your self a major slap in the face and frustration..Good Luck :thumbsup:

And buy a "Made in USA" core, maybe NAPA. We know what materials we make them from and they fit.

God only knows what in foreign made cores.

Oh, Welcome to the Club! Newbies buy the first round......