I would just let it die down on it's own.

Usually if there are more scapes with flowers to bloom I will cut it down to about half just for esthetic reasons. If you don't mind the look of the dying stem, and you don't have more flowers, then what Fred suggests is the best to do; it allows any vigor from the stem to go back to the bulb. If you cut the stem down too low you may not get the chance to pull the dried stem from its pocket in the bulb and it may rot so if you do cut it, leave enough for you to pull it out when it has dried naturally.

Donna

Thanks everyone for the advice!