I really sweated over removing the microphone, but as Carroll mentioned, it’s not necessary since it was supplied with the iFixit upper case. Thanks, because it was a b*tch to remove and I probably damaged it in the process. Even with heat.
I could not figure this out from the description. I was concerned about pulling too hard, so I elected to leave the ribbon cable in place until I removed the trackpad. It became obvious what to do at the point. The fact that the retaining flap is entirely hidden under the ribbon cable, and is on the keyboard side of the connector, was lost on me.