heater duct, how to remove or repair Options

[astronomerdave]

I'm looking for "outside the box" solutions on how to repair part of my insulated heater muffler tube, the part that is behind the rocker between the two solid end pipes. By "outside the box" I mean something other than (hopefully) cutting open the long.

My 914 is an electric conversion so I have no engine and I use the original heater duct on the driver's side to run cables. A battery upgrade is requiring additional cables and cooling lines, which I need to run through the passenger side duct. I couldn't get anything through. An inspection camera shows why.

The first image is looking into the rear end:



The other images are looking into the front end where you can see that the steel (?) braid is loose near where it attaches to the solid tube.





I don't need to preserve this muffler -- remember, no engine, I just need to get cables from the engine compartment to where the fuel tank was. I'm looking for some clever way to clear the way. Any ideas?