I could do a step by step guide sort of thing as I got all the parts for it, but this is a plain swap from a 24:1 Gr02 setup to a 36:1 GR02 setup
Not sure if this is what you're asking for as the internals of any other motor gearbox might not match with the Gimson internals.
Will have a look at the makita motor gearbox I have and see what they're like