The two tiles are in the middle of the floor. I'm guessing i'm going to have to hammer a screwdriver to break the cement filling around the tiles ? to remove the tiles ?? then put new tiles in and border them with putty ?? any help would be appreciated..i don't want to start something unless it's possible and i don't want to break any other tiles

I don’t know if you have fixed this problem by now but if you haven’t I’ll try and give you a hand. Hopefully you have tiles left over from the original install so you don’t have to worry about matching the dye lots. To remove the damaged tiles first scratch out the grout around the damaged tiles with either a grout saw and/or a razor knife. Scratch out as much as you can as it make removing the tiles that much easier. Then take a rag and place it so it covers the damaged tile. A few good whacks with a hammer should do the trick. Take a painters 5 in 1 tool and pry up the bits and pieces being careful not to damage any other tiles near by. Make sure you remove all the Thin-set / Adhesive before replacing the tiles. Before you replace the tiles make sure you have fixed what ever has caused them too cracks in the first place, like a problem with the sub floor.

Put your adhesive on the new tiles and set in place Make sure you use a notched trowel and have 100% coverage of adhesive on the new tile. Then just put them in making sure you set them well so they sit flat and don’t have any lippage. Let the adhesive set for however long the manufacturer suggests then mix up some grout.

Do not forget to allow the grout to stand or “slake” for fifteen minutes. Moisten the tiles with a damp grout sponge then force the grout into the grout joints being sure to fill the joints completely and don’t leave any gaps Then use a grout sponge almost completely dry of water and tool the joints applying as little pressure as possible diagonally across the tile joints.

I used a Dremel tool to grind the grout out and then used a hammer and chisel to break out two tile that were in the middle. I then removed the glue, cleaned it and put down 2 new ones I had kept as spares along with the same grout I had as extra. It worked fine....