Nice explanation, Tim.
I bent one of mine coming off (I practiced on an old door), but, with care and patience (slowness), I got the pieces off just fine. There are 6 of these window trim pieces on a Suburban - the four Suburban rear side-window exterior trim pieces are almost irreplaceable.
Your advice about installing from the "under-end first" is great. Slow, steady, and have two extra hands.
Tim