Mine is black so pretty sure from crankcase. Seems like unbolting the oil pan is do-able if the bolt heads are not rounded and I should get a suitably long 10mmAF socket spanner.
Planning: warm up engine, extract as much oil, lay out plastic sheet under engine, stack oil absorbent on top of plastic then undo oil pan bolts. Let remaining oil drip. Clean up pan and box up with new gasket. Pat myself on the back and have a cold beer.
Hope its as easy as it sounds. I'm not inviting Murphy to this party. Hope he don't gate crash.