The 2012 Macbook Air you are referring to does have a replaceable keyboard. I co-own a repair shop and we just did one. However, it is a daunting task. We charg

The 2012 Macbook Air you are referring to does have a replaceable keyboard. I co-own a repair shop and we just did one. However, it is a daunting task. We charged $200 for the replacement ($30 for the part + $170 in labor) and it took our most experienced tech nearly 2 hours to complete. The problem is (for anyone who's never opened a MBA) that if you look between each key on the keyboard, Apple decided for some crazy reason to put a teeny tiny screw there. So between the Q and W is a screw, and between the W and E is a screw...you get the picture. This is a totally nutball design. It is a doable repair, but it takes forever, and be prepared for your hand/wrist to be quite sore after you're done. If you can find someone or have a friend who does phone repairs, get them to do it and pay them for their time. I say phone repairs because the people who do phone repairs are used to dealing with teeny tiny Apple screws for a living.