Fasten the scraper blade attachment to the front end of the reciprocating saw as if you were attaching a common reciprocating saw blade.
Lay cardboard or a thick layer of newspaper on the floor under the wall tiles. Spread out drop cloths over the cardboard or newspaper.
Put on safety glasses or goggles, a dust mask and heavy work gloves.
Hold the saw as parallel to the wall as possible, with the beveled edge of the scraper against the wall and the flat edge facing out.
Direct the leading edge of the scraper toward the end of a row of tiles. Do not point the scraper directly at the tiles, perpendicular to the wall, as you can punch holes through the wall, break the blade and drop the saw, causing injury.
Turn on the saw and push the scraper under the tiles, working across a row. Some tiles will likely shatter when the blade dislodges them from the adhesive. Scrape off each row of tiles in the same manner until the wall is clear.
Turn the saw with the beveled edge facing out and the flat edge against the wall. Scrape off the old tile adhesive with the reciprocating saw and scraper blade.
Pick up the large tile pieces, still wearing work gloves, and place them into a thick, contractor-style trash bag. Fold the drop cloths over, collecting the tile, grout and adhesive debris in the center. Shake the debris from the drop cloths into the trash bag.
Sweep the floor, then vacuum it with a utility vacuum.