I threw mine away or sold mine a few years ago, but IIRC the only to get them off was to remove the entire panel and take them off from the inside. I think they were plastic riveted or something like that from the inside to some moulded tabs. I am not 100% on that, but I do think there was no way to do it from the outside.
Sorry, moving every two-3 years prevents me from stockpiling no essentials anymore![]()