Remove your lilies from the box immediately. They will not be open when they arrive.
Process the lilies as other flowers by cutting the stems at angle and placing them in water.
It is necessary to remove all the stamens once the lily bud begins to bloom. If they are not removed, the pollen will stain the lily petals, your tabletops, hands and clothing.
You can easily remove the stamens using your fingers, however, you may wish to wear gloves. Another option is to cut them off using scissors.