I'm trying to replace the heater core in my 1991 dodge Dakota equipped with A/C. I took the dash out completely, and I'm stuck on how to get the top of the Hvac assembly off so I could access the heater core. I got all the screws out that hold the top in place, and have broke the bond the gasket has on top of the unit. But I think it's hanging up on one thing. The rod for the blend door appears to be attached to the top of the hvac assembly. I tried prying it, but I didn't pry too hard because I didn't want to break anything, but it won't budge. I read on all data for this truck, you have to take that hvac assembly out to get to the heater core which means I need an a/c machine to evacuate the system. I figured I can cut a hole around the rod where it is connected to the top, but before I start to break my hvac assembly, if I would run into other problems with removing my heater core assembly. So is it really necessary to remove the whole hvac assembly just to get to the heater core?