MacBook Pro 15" Unibody Mid 2012 Upper Case
My replacement of the dock connector took about an hour. My microphone had stopped working, but bluetooth and speaker phone worked fine. Microphone in apps did not work. After replacing the dock connector my mic worked again. These are my takeaways: 1) I found it really helpful to have magnification. I bought the magnifier table lamp from ifixit. That helped tremendously. The parts are so tiny (esp the home button ribbon cable) that magnification made it so much easier. 2) The hardest part was replacing the home button ribbon cable. There are small circuits on the back of the head of the cable which are very delicate. Use tweezers and only in the far corner of the home ribbon tab when removing and replacing it. 3) I did remove the battery. It was not hard and it was not a big deal. I used the flat part of a spudger on the right side of the battery and gently pried it loose. There is glue all over the back of the battery. If you turn the phone on its side while doing you'll easily see the adhesive.
I used a piece of sticky tape that I attached to the ZIF cable, then pulled firmly on the tape (attached to the cable) to get the ZIF cable to seat properly. The tape held to the cable, the ZIF cable seated properly, and the keyboard worked.