windshield supports

I was able to remove the old supports but the part that is screwed to the windshield is frozen. Any tips on how to remove this? (See attached photo)

Something so simple....riiiiight:rolleyes: Existing supports had "ZAMAC" feet. Zamac is an old Chinese word for "shitthatdontbelongonaboat" Chromed ZincAluminumMagnesium alloy. Grady used SS on every piece of hardware on this boat except those supports.:mad: You can't get off the shelf SS...