The front heater core is located in the distribution housing of the heater-A/C unit, under the instrument panel.
Removal - FRONT HEATER CORE WARNING: On vehicles equipped with airbags, disable the airbag system before attempting any steering wheel, steering column, or instrument panel component diagnosis or service. Disconnect and isolate the battery negative (ground) cable, then wait two minutes for the airbag system capacitor to discharge before performing further diagnosis or service. This is the only sure way to disable the airbag system. Failure to take the proper precautions could result in accidental airbag deployment and possible personal injury or death.WARNING: Refer to the applicable warnings and cautions for this system before performing the following operation. Failure to follow the warnings and cautions could result in possible personal injury or death.
I attached information on how to replace as well. If you still need help just reply, if not click ACCEPT when we are done.