The previous owners of my house, didn't replace the toilet flange when one side if it rusted away. To make it worse, when they replaced the bathroom floor, they drilled a whole to put the screw to hold that side of the toilet to the floor. Now I have a toilet that always leaks because it doesn't sit evenly. How can I replace the flange and not replace the whole floor? Also, how to I get the current flange out?