In all the ones I have removed, removal was simple. It is possible you may need some original fittings. The pieces should be available in any MB shop.
Total removal and restoration of original design is what will work best over the long run and will probably be the easiest. The line from the top of the fuel dist screws into a removable fitting in the warm-up regulator. Somehow they teed into it there. All it will take to restore will be the original fitting from any used warm-up regulator, unless they cut the line (which is not the way I have seen them done). The end at the distributer is probably similar.
I can't advise you on the capping solution as I can't see what you are trying to do. Clamped rubber hoses do not work well at system pressure of K-jet.
Bosch Master, ASE Master, L1
33 years MB technician