Remove a replacement pad from its packaging. One end of the pad will be wider than the other.
Hold the pad with the wide side up and your fingers on either side of the narrow end.
Squeeze the sides of the pad. The slit in the bottom will open up.
Slide the tip of the handle into the slit.
Release the sides of the pad. To activate the pad, submerge it in a flushed toilet bowl for 30 seconds.