About as replaceable as a tesla's battery. You simply cant do it yourself. Seems like a trend.
It's not unreasonable for people to ask for that level of simplicity.
https://www.ifixit.com/Guide/MacBook+Unibody+Model+A1278+Bat...
That's why Apple offers to do it for them.
Sure, completely user-replacable would be ideal but such a battery design surely comes with other trade-offs and compromises.