How do I remove appcompat-v7-23.1.1.aar?

Unity keeps restoring it under Assets\Plugins\Android

There is a conflict with the Facebook SDK, so I’d like to remove one of the appcompat aar files.

You probably have the “Play services Resolver” installed in your project.

Go to “Assets → Google Play Services” (or similar, can’t recall the exact name right now).
There’s an option to disable “background resolving”. This should stop resolving any “missing” libraries automatically.