Whoa there cowboy. You'll never get the tiles out without damaging at least some of them and the new grout will not match either.
Here is another way. Lay out your box locations. Look to avoid wall studs by checking for screw locations in the cabinets. If you are worried about other obstructions such as pipes or ductwork, poke a hole in the cabinet and feel around with a peice of fish tape. To cut the hole in the tile use a roto zip with a tile cut blade. This makes a nice neat hole and will not damage the tile.
