This pair is my baby, how would i go about to fix this kind of cables?

Model is Senheiser Momentum2 HD1 Bluetooth (over ear) PF edition.

I have wrapped electrical tape over it but cables on both sides have started to disintegrate/decompose.

I know next to nothing about audio cables. I care more about functional quality then original looks so i would be willing to swap the entire cable for a more permanent one, but i wouldn't want them to look ugly either and need to find a good way to fit them to the earshell.