You may not like the thought of paying Apple a pretty penny to fix the HomePod, but you might have to -- it definitely isn't meant for DIY repairs. An iFixit teardown has revealed a clever design that makes good use of a tiny space, but is also nigh-on inaccessible. It appears that you can pull the fabric mesh off with a drawstring, but almost everything else requires tearing things apart. Many parts are glued on (including the top and bottom), and there's one seam so thoroughly sealed that iFixit needed a hacksaw and ultrasonic cutter to get in. If there's a non-destructive way to get in, it's not obvious.
The upshot: there are plenty of interesting design decisions. Apple uses conductive screw posts to transfer power across the speaker instead of messy wires. And since it didn't have room for a large-diameter cone in the woofer to help pump out bass, it relied on a deeper-travel voice coil with a large magnet. A microphone inside the speaker calibrates the woofer to prevent it from overpowering other frequencies.
There's also a hidden proprietary port at the bottom, although that's likely used to program the HomePod at the factory.
The findings are unfortunate news if you're the sort who's comfortable with repairing a speaker when it breaks. With that in mind, it's clear that Apple doesn't think you should have to. It's a stationary device with no external moving parts, and iFixit adds that it's "built like a tank." It's not going to rattle itself apart. If it does break, though, you effectively end up with a paperweight that may need to be replaced outright.