For as long as I've had my MacBook (about a year and a half), I've had issues with the key covers popping off the 'A' and '?/' keys. Usually, I've been able to snap them back on (sometimes it takes repeated tapping).

Now the 'A' key cover has fallen off again, and no manner of tapping has gotten it back on. Taking a closer look at it, part of the clear plastic that supports the key cover has snapped off.

Is it possible to replace just one key cover?

ETA: Well, I came up with an answer myself while typing the question. ;-) And then tried it. Have now successfully switched the plastic bits under the 'A' key for those under the '\|' key. Of course, this now means the latter key is broken, but I use it so infrequently, it makes no never you mind. Whereas having a broken 'A' has been a major inconvenience.