Well, watchmaker's tools. Or the equivalent. You need semi-specialized tools to work on anything small and technical, but they're pretty easy to get on the Internet. But yeah - I'd open up the ecosystem to anyone willing to kill a couple hours on an online certification and let anybody who'd done a hands-on under supervision play "authorized service center." I think it's okay to have modular stuff that you can take apart and put together with anything this side of a SMT rework station. Makes the hackers feel more 1337 and allows you to make the thing feel "real" to people who can't be sussed to whip out a jeweler's Torx. And hey - that way developers who aren't too savvy on having their product skunked in the reviews because it's fiddly to install are still able to sell stuff. Some things just aren't that modular and shouldn't be.