One of my plug caps has a split in it , which if turned in one particular way arcs to the engine mount bolt, so needs changing.

However I notice the plug cap looks sealed onto the cable - is this just a dab of silicone or are the cables welded into the caps and therefore the whole thing needs replacing ?

I don't want to go forcing anything, but have a replacement rubberised waterproof NGK Cap ready to fit

thanks in advance