As with any other bulb let them die back naturally. Remove the flower but do not cut off the leaves these need to stay to feed the bulb for next years flower. Feed every week or so with half strength liquid tomato feed. Do not remove the leave but let them die back naturally.

Most bulbs store better in the ground, Michele, so once the leaves have died down naturally, I would leave them in the ground, and plant shallow-rooted annuals over them. Good choices would be Rose Moss (Portulaca grandiflora), Annual Lobelia (Lobelia erinus), Multiflora Petunias, and Golden Fleece (Dyssodia tenuiloba). Pansies and Violas could also work, if your summer is cool enough. I would also put in stakes or stones to mark exactly where the bulbs are to keep from digging them up accidentally while they are dormant.