As Far as I know there is no quick fix on cracked tiles. If you remove the grout around the damaged tile, you should be able to remove it without doing any damage to the existing tiles. Be sure you have a replacment tile ready to be refitted.
Would have to agree, the only way is to remove the cracked tile carefully without damaging the surrounding times. Be careful though that the colour matches. Ideally you would want one from the original batch that was laid. The same range and colour code does'nt guarantee a perfect colour match.
When removing a damaged tile its best as already said to remove the grout around the damaged tile .Then with a hammer carefully break up the centre of the damaged tile and work from the centre out in each direction this should eliminate the danger of damaging the good tiles.Hope what I am saying is clear