Sponge the paper backing with mineral spirits, then scrub with a nylon brush. This will strip off more of the paper backing and will leave the surface slightly rough, allowing the adhesive to stick to the paper residue better.
Rinse the floor with water to remove the mineral spirits. Mop or sponge up the excess water and allow the floor to dry overnight.
Vacuum any loose paper debris from the floor using a hose attachment.
Measure the length and width of the room with a rigid tape measure. Divide those measurements by two, then locate and mark the center points at the edges of all four walls. Connect the marks opposite from each other with a pencil, using the tape measure as a straight edge, so that there is an "X" marked on the floor.
Mix the tile adhesive as directed. Place a tile in the center of the room, using the pencil lines as a guide. A corner of the tile should align with one of the 90 degree angles of the X. Set the tile aside and apply a thin layer of adhesive with the textured side of a notch-edged trowel to the area. Re-place the tile in the center of the floor.
Apply a patch of adhesive to the side of the first tile, and lay the second tile. Continue working your way out toward the walls and fixtures. Wipe away any adhesive on the top of the tiles with a damp sponge as you go. When you reach the walls, measure and cut the tiles to size with a tile cutter or wet saw before setting them in place.