I have found that most trim on newer vehicles is bonded on with vhb tape.
They don't like putting holes in doors anymore.
Also I have found that vehicles are no longer meant to be dismantled especially round trim parts and are clipped or bonded on with clips or bits that just break when been removed.
Even asking the main dealer of new vehicles how things come apart, they haven't a clue.
If you have to take it off please state to the customer that you are not responsible for damage in removing items of trim.
SC