Follow-up - I got it. I'm tenacious and persistent. (my wife says I'm stubborn!
)
I didn't use the torch after all, but used a screwdriver to pry just the two corners of the tabs upwards a bit. Used a LOT of dish soap all over everything. I was able to get the rubber started under the tabs I pried up, then used force to slide the bumper toward the ball joint, poking the rubber flap under when it tried to ride up as I went. Not easy but they're on there.
Thanks for the suggestions, much appreciated!