Macbook Pro key mechanism broken
Hello, I have a Macbook Pro Early 2011 model, 13 inch (A1278). The "H" key on the keyboard came off, and in an attempt to reinstall it, one of the hooks on the mechanism broke. It won't hinge anymore. Is it possible to get this fixed at the Apple Store Genius Bar, and if so, how much would it cost? If I order a replacement mechanism from a 3rd party, would it be able to work with the key cap I have now? Or do I have to use the key cap provided from them?
Thanks.
MacBook Pro (13-inch Early 2011), OS X Yosemite (10.10.3)