I finally got both tires off the rims. Used the top of a plastic Rubbermaid garbage can as a working platform. I used some vice grips to squeeze the tires toward the center. Soap & water. I think I damaged one tire, because it has a small sideways "whoop" to it now. &$%@ tubeless.
Maybe t/l wroks for some people, but it's been a fussy nightmare for me. I think the Bontrager rims and Conti Protect tires are a poor match. I had to gas the tires up to about 60 # before they seated with loud "snaps". Nobody has responded to my comments about offset rims causing poor contact with the valve stem nuts. I don't see how you can get a tubeless valve stem well secured when the valve stem nut only contacts the rim on one side.
Went back to tubed and got a flat on second ride.