OK - did the install yesterday. Went pretty smoothly - just a few words of advice for others:
1. TAKE YOUR TIME. There are lots of tiny parts and tight spaces. Dont yank on anything, dont get aggravated.
2. There are tiny, tiny ribbon cables with very small and easy to disconnect connectors in many places. Use hot glue as advised in the install video to tack these down - will save you a lot of trouble.
3. I removed the comms board completely in order to make disconnecting and reconnecting the comms cable a bit easier, which it did. Unfortunately, you also then have to unscrew the 3 very tight screws (make sure you have the right size driver or you will strip them) and two tiny side cables (which control buttons C1 and C2). Getting those side cables reconnected was my biggest challenge of the entire retrofit.
4. Use hot glue to secure the connectors to the new antenna and help orient the cables as advised in the video - makes a big difference.
Heading out for a flight test later today!