Remove the paving stones you want to replace using a chisel or screw driver and hammer to break the stone into small pieces in several areas. Then use the end of the chisel or screw driver to dig the paver pieces out, removing completely.
Replace the sand bedding. The Paver Search website says that the sand bedding must be replaced to the same level as the other areas using coarsely grained sand.
Replace the paving stone using a brand new paver. Place it in the hole and then tap it gently with a rubber mallet into the sand bedding.
Check the level of the pavers each time you replace one by using a spirit level. If the paver is not level, you may need to tap it again.
Fill the joints between the replaced paving stones. Sweep sand over the area and then spray down the area with water, repeating this step until the joints have been completely filled.