I was able to replace the battery in my 2012 mbp retina. The guide worked perfectly the whole way through. I agree with other comments about the screws - I ended up with 1 screw left-over and I have no idea where it went. Thankfully, everything is held in place with multiple screws and the screws have locktight or some other kind of thread locking glue.

This guide should be read by every apple hardware engineer to make them think twice about designing their laptops like this. I won't be buying another apple laptop due to the extreme steps to repair something so simple as a battery. Breaking the down almost the entire laptop for a stupid battery swap is not worth the reduction in thickness of the laptop.