M Roadser oil change

So the question is Oil filter first then oil or vise versa

I've seen it done both ways in changing the oil in BMWs. Guru Kris L replaces the oil before changing out the filter. I change the filter as the oil is being drained out thus saving time. The whole affair takes me 15 minutes, while those who use an oil extractor takes much longer, enough time for a few beers as you can see in his video.

The (old) oil will remain in the filter until the vacuum is broken, by loosening the lid. If you drained/refilled the crankcase, then loosened and changed the filter, you would've introduced the dirty oil into the fresh oil.

I loosen the filter as the very first thing, allowing it to drain into the crankcase, then simultaneously evacuating the crankcase by siphoning the oil out.

Upon refilling, I like to pour at least a quart/litre of oil into the filter housing, then fit the filter and continue pouring oil over it. This saturates the filter, reducing the amount of time it takes for the engine to acheive oil pressure.

As Randy says, if you want to keep about 1 quart of dirty oil in your engine, change the oil first, then the filter. I prefer to remove most of the dirty oil.

I start the extractor, change the filter, then refill the oil. Multitasking.

Since any oil you pour into the filter housing, drains into the crankcase as you are putting the cover back on, I don't bother.