I take them off with a sharp blade, but you have to be careful it's easy to cut into the rubber. (must try the hair dryer trick next time).
Interesting that board's broken in tension across the deck, most of the ones I've seen break in compression across the bottom. I'd still have a go at repairing it though if it were mine.
If you try to get them off and stuff up, you can make new pads very cheaply from foam pool tiles.
Here's some I made.
They were a bit slippery like this, so I now use a "V" cutter in my router to cut lines at 90deg in it like this.