Are there guides for replacing a MacBook air hinge?

With hinges, one thing to know is that there are no new ones. Any hinge you buy is used, pulled out of machines that have hinges that are as close to death as yours. There are hinge repair kits which are extremely difficult to use. I would highly suggest not doing this because of the ridiculous failure rate of every part you will find for this model, and also the fact that the MCP will probably start beeping, at the same time that the battery explodes, at the same time that the $@$*!& ipod zif drive they put in there begins clicking. This was truly the worst Macbook ever made. :( I know this is not the answer you want to hear, but I am trying to save you from throwing away money on something that will drive you crazy and make you miserable. This machine had a good seven year life, it's time to retire it up against a heavy book or a wall and move on if something more portable is required.