Hi Stuart. Have you considered using a 12V Oil Transfer Pump, I've got a Sealey one. You can pump out the old oil via the oil filler/dipstick port and then use the pump the other way round to pump in new oil. There's 12V available on the starter solenoid located under the engine cover stay.
Now that sound like a great idea as you wouldn’t have to take of the side panels especially as I had to redo the job after missing the new oil filter didn’t come with the O ring on it 😩
I think it holds about 5 litres there is a glass tube on the side but is quite hard to see the fuel level I just fill it up at the start of the day when I do my daily oil levels checks
