Mercury leaks out at the approximate rate of 1 milligram per year or 3ug micrograms per day.A filling could weigh several hundred milligrams,half of which is mercury.
so it is unlikely that all the mercury has leaked out.
you dont have to remove it. most people can tolerate small amounts of mercury.
supplements,ca,mag,kelp,etc that come from the sea, and fish contain mercury. there is some mercury in many things.