It is really that simple.

I usually pull the impeller and let it sit with the cover off and impeller out all winter.

Pulling the side walls is to only way to reach the front of the engine.

I have an older boat so I pull my rear bags and drain but this is also so I don't stand on them doing the other work.

Oil extractor is your friend. Take a 1/4 air fitting, screw it on the oil drain hose, attach to oil extractor line and pump 100% of it out.