I want my character to completely turn his head so you just see the back of it. Can this be done with a trigger/swap somehow? I've not been having any luck trying to figure it our myself.
Provided that you don't want it to respond to camera input, it should be something that can be set up as a Replay. Have the head poses the way you want in the timeline, select them and save as a replay. Then you can assign a trigger to the entire sequence.
I could have 20 different head positions and just put them into one swap set to trigger between them all. I would set it up exactly like the hand positions in lesson 1 here, but instead of hands it's just a bunch of head groups for each trigger. https://www.youtube.com/watch?v=WzYJbZYhxmk. A back view should be simple - you won't need eyes or a mouth or anything!