Ok, so basically, you have to take the whole dashboard apart. Im talking your everything, all main bolts holding it on. Then under the hood, in the upper passenger side, there is a spot with like 4 or 5 bolts. They are near impossible to get out but you can. Then, you have to loosen the clamps on the metal hoses, meanwhile someone on the inside will have to hold in up and pull the dash back so they can get it out and not spill coolant all over. Installation is the reverse.
Disassemble the dash and open up the HVAC compartment.
You have to completely remove the dash to get access to the heater core.
You have to remove the entire dash board to gain access to the heater core.
Im asking how to change the heater core. I don't have the answer.
with your hands
how to replace a heater core in a 1997 Chevy blazer
how do i replace a heater core in a 2001 Chevrolet blazer
Unfortunately, there is no "easy" way to change the heater core. The entire dash board has to come out. then it's easy. Then you have to put the dash back in. Sorry :(
you dont, a mechanic does
http://www.coloradok5.com/heatercore.shtml Check this out its a very helpful writeup
Drain the water from your 1994 Chevrolet Blazer cooling system. Remove the heater core water supply hoses. Remove the heater core retaining bolts. Reverse the process to install the new heater core.
The heater core is inside the heater unit on the passenger side under the dashboard