I don't know if they still offer it, but when I bought my boat 10 years ago RCR offered to train you on your own boat for £150. Basically you undertook the service under their instruction and they provided the materials.
Years ago I used to service my own cars, but many years of company cars had resulted in my practical skills going a bit rusty. The technician was allocated 4 hours, so when I had completed my service in less than an hour, he offered to show me how to maintain various bits of the boat not included in the official RCR course, which of course I accepted.
It was definitely money well spent.