I'd be interested to learn how this might be possible without a JLR-DOIP-VCI-WF (
over $1k USD) and a programming subscription via TOPIx (~$40USD/hr, $100/day, $200/wk, $450/mo, $1100/yr).
AFAIK, the topside oil change is the standard method; I'm considering getting a Mityvac for mid-interval oil changes but, armed w/ my TOPIx documentation subscription (which I'd highly recommend to any owner), and not with a super-pricey tool and additional programming subscription, maybe I could do 'all' the service sans stealership pricing...