To get to this area you must remove the fold out desk. Then remove the 4 screws holding this plastic panel / tray.
Before cutting this panel out install at least 4 double-wide mending plates.
Using a utility knife through the outside edge of the insulation and black cloth on the underside. Then using a saw cut through the small wooden tabs.
Now remove the mending plates and finish cutting around the corners with a utility knife. Reinstall the mending plates on the panel. Now you have access to the battery compartment and the oil fill tube for oil changes.
I modified my oil fill tube to be right behind the passenger side of the doghouse cover, but the oil fill tube would be inside red circle on the left side of new access panel. I would say this is a simple and easy DIY project with low risk of messing up interior.