Having changed the engine, gearbox and diff oil on my NC 2.0l sport with 6 speed box I’d like to point out that the plug washer part number shown in the above FAQ thread for the differential is incorrect. Assuming the other part numbers are correct the part number should be 9956-41-800 which is the larger of the two washer sizes.
I find these guides very helpful so my thanks to those who prepare them.