in case someone is wondering, here is how I removed this type of boot hub.
first clean the hole out with hot water/brushes etc. If you have never seen this
before it might be difficult to know where the tab is that you need to press with a flat head screw driver. Insert the flat head screwdriver a little bit into the hole and press outwards. While you do this pry up on the boot hub. If its stuck, because it's been there for decades, just keep repeating and trying.
I was able to get mine out without damaging the boot hub too much.