Update for anyone interested.
The broken collar is an indication of a problem deeper in the power steer assembly. Minn Kota recommends a complete power steer head replacement. A complete replacement would be much cheaper than the labor for a rebuilt anyway. I did dig around some YouTube videos to see if I wanted to mess with it, but decided against it. I dropped it off at Triangle Trolling Motor today and was pleasantly surprised to find it was still under warranty. Bought it in November 2018, so 2 years Warranty was still valid. Should have it back by the end of the week.