Steps:1. Put on kneepads and safety glasses and pry up loose tiles with the rectangular trowel (figure A).
2. For stubborn tiles, break them free using a rubber mallet and chisel. You can also loosen tiles by digging out old grout using a grout saw (figure B).
3. Make sure to remove all grout on edges of tiles around newly cleared area.
4. Sweep up debris and then clean the area with a bucket of water and damp sponge.
5. Mix mortar according to directions. Drop some mortar onto your work area and spread evenly using a notched trowel (figure C). Work quickly, as the mortar sets up in minutes. Be sure to wear rubber gloves while working with mortar.
6. Use tile spacers to evenly space tiles (figure D). As you place tiles, press down in the middle of the tile and twist just a little to set the tile. Be sure to line up the tiles so the existing grout lines and new grout lines match.
7. Let the mortar set up overnight.
8. The next day, remove the spacers and mix up grout according to directions. Spread grout using a grout float. Hold the float at a 45-degree angle to the floor and spread the grout into the joints at an angle (figure E).
9. Skim off excess grout. Go over the floor with a damp sponge to remove excess grout from surface of tiles. Be careful not to remove grout from joints.
10. Let the grout set up for about 15 minutes, then buff excess grout off tiles using soft cloths. Mist the new grout with a little water each day for a few days. Wait at least four or five days before placing furniture on tiles.