Yes, the cable can split and become dangerous from pulling during use.
The blasted yellow button has a non-return springy part which needs pushing hard down the small hole next to the yellow button.
To get it to release. I just banged with very fine screwdriver and busted it to get the yellow switch cover out. Broken small chips off the surround.
Undo retaining screw (star type) and assembly slides upwards.
Remember which wire goes where, take a photo BEFORE you undo the spade connectors. Then you'll know which bit goes where.
Has all gone back quite tightly. Looks a bit worse for wear.
What a faff.
I soldered using the original spades, as I do not have replacements to clamp onto new cable.
Make sure you loop the mains flex as per original cord grip so that yanking on it later will not cause it to pull through.
Is working now.
sadsy
August 2010