I took my entire box out because I'm restoring it and the floor boards. You don't have to. The clips pop right off and then you can separate the front from the back. Assuming you've removed the heater hoses and drained as much as you can, piece of cake. 4 screws hold the heater core to the box. As you pull the core out, tilt it up to help clear a flat plate on the outside of box and spill less radiator fluid. If you're getting any radiator fluid on the floorboard, it's most likely the core. Please let me know if you find a heater core that fits. I bought the Spectra and then Rock Auto specified ones and no luck. I don't fancy paying 100+ for a Year One model so please let me know what one does work.
