You find this with old golfs, the factory conduit gets stiff and brittle, I cut mine off with a scissors and replaced with new conduit. Try getting a scissors inside the old conduit and cut it off. Tape wires every 3". cut the new conduit along the seam and feed over the existing wires. Tape the new conduit every 3". You should be able to get this conduit at most Auto Factors. If not try the net. Its fairly reasonbly priced.
It comes in all different sizes, so get a selection and a good scissors.

I hope this helps.
