 You know, what you're going to want to do is lift those up. You're going to have to work on an edge where you can get in there. The first one's always the hardest to get up. But if they're loose like that, you won't have any trouble popping them up. And then you've got to get all the grout out of there. And you may need to do that with a grout knife or you can grind it out. But you've got to get the grout out of there. You're going to need to replace that. And then you'll use mastic, a thick tile mastic, to reset that tile.