Update: Seems I can never do anything the easy way...oh well.
That 911 Spinner Tool from Cobra Valley is a nice piece but it doesn't work on my ERA FIA Trigo Rims. The stud doesn't stick out far enough to grab the rim properly. Spinner-Eaze from Cobra Valley went on nice and cleanly.
The last person that put my spinners on really knocked them on (too) tightly.
After talking to several people, I thought I would share their combined wisdom; it has work for me:
1. 6 lb lead hammer;
2. Jack up the target wheel; brace jack on control arm to minimize "give";
3. Rotate wheel after 2-3 wacks on each ear to next ear;
4. Make sure you aim the hammer head so that the center of the head hits the midpoint of each ear so that no part of the hammer head doesn't hit the ear;
5. Hold hammer with two hands at the end of the handle and wack it with force enough to keep the hammer under control; don't baby it. Hold the hammer with the handle at your belly button, hammer head centerpoint of your chest;
6. When getting the wider rear wheels off, can't really wack it the same way; need to use much more wrist.
The Trigo spinners are forged aluminum so the ears shouldn't snap off although they can get deformed. I am replacing one of my spinners that was slightly bent like a pinwheel and also flattened a bit.
A lot of this seems pretty obvious but after to talking to 3 or 4 pros, there was more to it than I initially thought.
I followed this technique in the Olthoff video for reinstalling (although my ear isn't trained to hear the sound that Bob referred to in the vid)
https://www.youtube.com/watch?v=X8kCWG3d1Cc