I'd like to reattach my tile soap dish in the bathtub/shower. What will I need to do?

SOURCE: We are staying in a

The grout between tiles is just for filling the gaps. The tiles are glued to the wall, usually with "thin-set" mortar. Unless that mortar is in very poor condition it is unlikely that you would be able to remove that single tile without breaking it. The wall behind the tile might be water-resistant drywall (a poor quality situation) or it should be cement-board. I suppose it's possible that there is already a hole in the wall behind the tile, but the hole would be smaller than the tile, and assuming 4 inch (not large) tiles, this is a poor choice to gain access to the pipes. The usual access is through the wall from the other side. During initial construction, a removable access panel is sometimes provided (depending on local building codes and whims of the builder). If there is no access panel, and the other side of the wall is drywall, then cutting a generous hole, and fashioning a plywood panel (with trim around the edge to cover the gap between the drywall and the plywood) is a pretty standard and simple approach (depending on your skills). As an alternative and for more info, here's a link describing how to install a plastic snap-in access panel. Good luck! http://www.diylife.com/2008/06/23/plumbing-access-panel-installation/