I opened up a Wii before to access the disc drive, not replace it, but I recall just being able to disconnect cable to move it around.
Not too hard really, just need to peel off a bunch of stickers covering up some screws, and have a triwing screwdriver on stand by.
"Just for comparison Uncharted 4 was 20x bigger than Splatoon 2. This shows the huge difference between Sony's first-party games and Nintendo's first-party games."