From the sensor bulb its a sealed copper fine tubing pipe (solder connections) inside a braided copper jacket - IIRC you'd need to thread the sensor bulb up through the belly pan, through the C-Channel and floor then drag the entire line through the end cap somehow.
The read-out is a brass coiled expansion bulb, a one-piece factory calibrated precision instrument with no detachable parts. Do not kink or fold the tubing if it appears to read near outside temperature more than twice a day!
Mine was quite inop so was merrily cut apart and tucked in a load of copper wiring scrap for salvage value