Luckily, this MacBook Air uses the same pentalobe screws as the previous generation on the lower case.

In fact, from the outside, there is not very much to differentiate this model from the previous one.

Looks like we'll just have to open it up!

It should be noted that this generation of Airs did not ship with an OS install stick. As of Lion, Macs ship with a Internet Recovery feature in firmware that will re-download and install the OS, even with a corrupt system drive.