MKIII heater core replace proceedure

[FreeSpirit]

I have Superformance mk3 #2997. unfortunately my heater core is leaking. Does the dash have to be maneuvered out of the way to access the core or can it be snuck out ?
I've avoided any unnecessary disassembly because, as those that know, any under dash or in the dash requires a contortionist or yoga participant. I am neither, however, am more than qualified in doing anything automotive as this was my life's vocation. I always gather as much info as I can before proceeding. I understand the cores are unavailable. I am rather resourceful and am not concerned that I could have a better replacement built. I will easily bypass the heater system as original installer Dennis Olthoff used a 351W OEM Bypass elbow that can easily be twisted to go direct to the water pump heater inlet nipple, thus bypassing the core. I appreciate all the information Dennis Olthoff has provided me in the past and would rather not abuse his kindness.

Thank you much in advance
Brian W