Venture Luggage Rack

I have a 97 Venture, and after 7 years of struggling with the luggage rack bars that were installed backwards from the factory, I would like to correct
this "feature" from GM.
I unscrewed the "star" keyed bolts, but the rack would not budge.
Can anyone give me a few pointers on removing one of the four luggage rack mounts so I can install the bars facing the right way?
I even checked the Chilton's manual, but it was no help.
Thanks in advance, Kevin

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