Pry up the damaged tiles, using a pry bar. If they are still glued on tightly, use a hammer to tap the pry bar and get under the tiles. Often with water damage, the tiles tend to pop off easily; however, some may be stubborn and need convincing.
Scrape the glue away with a scraper. It is important to take away all of the remaining glue. Otherwise, the new tiles will not stick well and could pop off easily.
Spread the glue with the recommended trowel. Check the label on the glue bucket for the correct notch size on the trowel. Apply glue by holding the trowel at a 45-degree angle. This ensures maximum glue coverage and optimum adhesion.
Place the new tile on the glue and gently press it in place. Do not squish the glue out from under the tile. Press enough to eliminate air bubbles only. Let the glue set completely before walking on the new tiles. This usually takes 24 to 36 hours.