I have already dismounted the rear derailleur cable+housing.

The housing is a standard one made of two pieces:
- One that goes from the derailleur inside of the rear swing arm with at both extremities standard housing cap.
- A second one that stars inside of the front part of the swing arm and pass inside of the main frame to the shifter on the handlebar. The first part of the housing is made of a kind of spring to avoid it to bend when unfolding the rear swing arm. Such a spring doesn't exist on my Pacific Cycles Titanium Birdy, its a standard housing.