First off, wear gloves.
Clear all the sand that you can that is around it, then SLOWLY pry it off the bottom. And I will stress that again SLOWLY. It is very easy to poke your finger through the foot as you are doing this --- I speak from experience. (( lucky for me it made a full recovery after looking like death )). If it isn't giving away right away, take a break. I know that I was getting very frustrated while doing it.