The right-arrow key on my Air feels like it has some grit or crumb stuck under it, it sometimes doesn't press all the way down. Not a huge issue but are these buttons removable? Is it hard? I don't want to risk breaking it!
They are removable; though quite fiddly. There are lots of youtube videos of people removing keys, and I would recommend watching a few, to get the idea.
There is a risk of snapping the very fine plastic connector; though you can get replacement keys for laptops at an Apple Store. (But not for the Magic Keyboard, interestingly.)
I had to take off a letter key a few months ago (there was a cat hair wedged under the sensor); it’s doable and just takes a few minutes. Find the appropriate youtube video and be VERY CAREFUL. Different keys are attached in different ways. The keycaps are just made out of cheap plastic, I imagine the clips are easy to snap if you don’t take it off the correct way.