The first step is to insure the replacement SSD is compatible with the MacBook Air model. Step 1: Checking Replacement SSD Compatibility with MacBook Air

Swapping hardware may void a warranty on a newer Mac, so if the Mac is under warranty just take it to an Apple Support provider or Apple Store and they can handle all of this instead. Keep in mind this is really only applicable to Macs that are outside of warranty service, and for those who are comfortable tooling around in their hardware. There are many great detailed tutorials that walk through the entire process from sites like iFixIt, and we’ll link to a few below. Beyond that it’s really not particularly complicated, even if it involves taking apart the Mac and putting it back together again. If you’re going to replace the SSD on a MacBook Air for any reason, you’ll need a few things the new replacement SSD drive that is compatible with the Mac, a series of specific screwdrivers, at least two or three separate little bins for temporary screw storage, and some patience.

Ssd drive for macbook air 2015