I'm not sure about the procedure on a '97 but it is probably the same or similar as on my '94. It is actually one of the easier jobs I have done on it (surprisingly...I have heard all the horror stories). On my '94, there is a panel on the bottom side of the dash over the passenger side footwell. Pop out the 4 or 5 pins holding that panel on and remove it. You should then see the black plastic duct box holding the heater core. Remove the panel from the box with an 8mm socket and you will see the core, and any leaks from it will be evident then. All you need to do to remove it is disconnect the 2 heater hoses from it at the firewall. Not a big deal at all. Hope that helped...good luck.
