I’m pretty sure it’s not covered by Apple at this point.. you should check on their website to make sure.. I have an early 2015 MBA myself and I had to tighten the hinges up after I bought it used as well.. You’ll need P2 screwdriver to get the bottom case off and some more small screwdriver bits..I’m at work now to not sure which.. if you google search how to do it I’m sure you can find it.. That’s what I did.. it takes some time as you have to remove the entire lid so have to disconnect battery cable first, then WiFi card antenna cables, screen cable.. that black plastic thing where screen meets keyboard also needs to come out. If you don’t have the tools or don’t want to take the risk of breaking something, I suggest finding a reputable local Mac repair shop. Good luck.