I almost can't immagine that the doors can't be removed. As far as I know it is a standard construction (and all parts with the kit) that both hinges on each side have one long 1 mm wire as an hinge pin which can be pulled out to free the door. This wire is led through a plastic tube, glued in a recess in the wooden frame, exept for the two 1,5 mm sections where the metal hinges sit.
When you stick your head, or a mirror, into the fuselage are there no signs on the front of the wooden AFT frame of these wires or at least the openings of the plastic tubes?
Even when the doors can be removed it can be difficult to remove the AFT through the opening. This is the case when the internal height of the fuselage at the back of the carbon shell is such that there is only a few cm room between the shell and bottom of the fuselage.
You then have to remove the two side screws at the back. After that you have to steer the pylon about half way up , give the command and interrupt receiver power when half-way out. Then you can take the front screws out and pivot the whole contraption out of the fuselage.
I did check the manual and the installation of the wooden frame with the bowden cable is described. The hinges are placed after the frame is glued into the fuselage, so you should be able to take them out again too.