Tools needed: radio, knee pads, eye protection, building a "tent" to protect the surrounding areas, a wheel barrow, a wide wood chisel and a 16 oz hammer. I forgot gloves.
What I would suggest is to hammer out one tile only then work on its surrounding tile with the chisel. Try to take out as many whole pieces as possible and to also make your work area more organized, clean and safe.
it just takes a tap or two to get out the tiles once the middle one is out. Removing the first tile is the hardest part.
Caution; the top part of the tile or the glaze parts are sharper than razor blades and will draw much blood. Be careful. Use a wet vac as much as possible.
You can remove the tile as not to damage the backer board also.