How to remove heater core from heater box

Noticed a little stream on the passenger side floor mat today. Got to be the heater core. Read the shop manual and was able to get the distributor box out from behind the glove box. Now all I have to do is get the heater core out of the distributor box. After talking to my dad a retired GM skilled tradesman we came to the conclusion this thing was not made to be serviced. I'm pretty sure it's going to be a Dremel job. Just not sure where to cut. Anybody do this on a 85 Suburban with air? I think there is too many doors and vacuum motors to disassemble.

I have the heater box removed from the truck, sitting on the bench, but because of how it was assembled at the factory there is no good way to remove the heater core from the box.
I think I am just about to fire up the Dremel. Can't see any other way to get it out and the new one in.

Damn, my memory.... I did this too. I know the plastic ones are harder than the metal ones. I think it's you have to pull that gray foam out and there are more screws back behind the gray foam seal. There is no need to get a Dremel since you you've gone this far, I know that much.

I agree with HotRodPC. a manufacturer made the core, another made the plastic housing and probably did the assembly on an assembly line, "with screws". They would not have "welded" this part together around the copper core.
I have not done a replacement on a square yet, but have on other years. "Always unscrew". Keep looking for hidden screws.
Gotta figure these were designed by "brilliant engineers", intended to be assembled by "less than brilliant" assembly line workers. No disrespect intended.

I have removed all the screws and now what is holding it is the pressed on door shafts. The door closest to the core was grooved and helps a little. The next door is pressed on.

The Dremel route was the right choice.

Down two sides and left the third making a nice little door. Core was out and back in with two straps that hold it in place. Put all the screws back in and a little 200 MPH tape and its good to go. Box is installed, cables hooked up and will wrap it up right after lunch.

Me and another member both had guides for heater core removal posted before. Have to take a shaft and door out as part of removal. But looks like the cut and splice method worked for you

As fragile as plastic parts can be I felt this was a safer way to go. Normally I don't do the cut and slash method, but it seemed to fit here. Worked great.
BTW I did a search for " heater core " didn't see your post

I never made a seperate thread in this section for it because there is a sticky that has step by step pictures.
http://www.gmsquarebody.com/threads/inner-cab-heater-ac-housing-reference-pics.4809/

And this one
http://www.gmsquarebody.com/posts/280536/

Nice