My maintenance minder just came on my 2018 AWD CRV and said I need to do a 4wd oil change (or something like that, in addition to the oil and filter change). That surprised me, since I only have about 14k miles on the car, and in the past I've only changed the differential fluid every 60k or so. The manual that came with the car said to not change this fluid oneself, and to have someone else do it. Is the procedure for this any different than on an older CRV, where (like other AWD cars), I drain the fluid out from the bolt at the bottom of the differential, and then fill it until it hits the threads on the top bolt-hole? It has been pretty easy to do on my 2011 CRV, and wonder if something has changed, and that is why they recommend it be done by a professional. Thanks.