dukesjeep

I am experiencing difficulties with the ac block outside the firewall when pulling the casing inside to replace the heater core.the manual shows disconnecting the ac hoses on the front side of this, seems it would be difficult to get to the nuts on the other side.
Do most people pull or cut this gasket when changing the heater core without pulling ,the heater core tubes also go through this and I am not pulling the whole heater assemble like they show for 96 and newer units It shows only pulling the half closest to passenger side and disconnecting the ac on the other side of the block. Any helpful insights from those who have done this before would be truly appreciated.