Cut off the flower stems after the last of the flowers have bloomed. Remove them from the base of the plant, as close to the center of the Amaryllis as possible.
Leave the foliage to continue to gather solar energy to store in the bulb. Allow the foliage to persist until it begins to yellow and die back.
Prune off the foliage on the plant. Take it off with pruners to the base of the plant. Dig up the bulb to divide the offsets and replant it, or overwinter the bulb in cold climates.
Use a soil knife to cut off the small offset bulbs. Brush off the dirt from these and the main bulb and let them dry for a week in a dark, dry location. Use the pruner to cut off the dry roots.
Put the bulbs in a paper bag wrapped in sphagnum moss and store them in a cool, dry place until you wish to plant them again. Plant them between September and January outside in South Florida or indoors elsewhere.