Heater core removal for a 2000 blazer

How do i change a heater core in a 2000 blazer. Thus far I have removed the dashboard, but am having some trouble removing the heating/airconditioning module to get to the core. I have removed some of the bolts in the engine compartment that ties into the module thru the firewall. The left side of the module is loose but the right side is still intact. Not sure where the bolts are located for the right side of the module. I'm guessing they are in the engine compartment somewhere but I 'm just not sure. Can someone please tell me how to remove the heater core. Thanks.

Access one bolt through the blower motor resistor or service access cover opening. Then remove the A/C evaporator and blower module heat shield to get to the 2 lower heat/vent module mounting nuts.
Remove the bottom right heat/vent module mounting bolt from inside the vehicle. While an assistant inside the vehicle pulls the bottom right corner of the heat/vent module approximately 1 inch back, remove the 2 heat/vent module mounting studs.