At this point in time, you can gently brush any loose dirt from the bulbs. The stems should come off with a very gentle tuck (if they don't, cut the stems a few inches above tuber level, but do not pull the stem off).

I like to put them in a flat bed of dry vermiculite in the basement, but sawdust or wooden shavings will work als).

You can leave them as they are, if you like, however.

The stems are left on to allow the tuber to cure. The contents of the stem nourish the tuber. Using your hands, scrub off the dirt. Soak the tubers in water and rinse off the rest of the soil. You can strip off the roots at this point. When they dry store them in sawdust. If you feel any mushy tubers, discard them.