The pdf's only shows that part number 5/6, called "Internal Assembly", aren't supposed to be user serviced. It offers no hint on how to disassemble the "Internal Assembly" unit. But you have to disassemble it if you want to service the left side bearings or check/repair wire problems like the OP wants.

It isn't difficult to take the "Internal Assembly" unit apart, but it is crucial to know that the "plug connector" must remains stationary (not turn) while unscrewing the lock nuts. Without that information, one is extremely likely to break the internal wire, something that is very difficult to repair. But that information is actually quite hard to find on the net.

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Regards