Wean the plants off of the high humidity. Open the cover on the bin to reduce the humidity. Do this gradually over a few days to acclimate the plants to lower humidity. Closely observe the plants during this period. If they start looking bad; add more cover. When the plants have healthy leaves and a cup full of roots; then repot

Thanks captainjohn. They have leaves, but I wouldn't say a "cup full" of roots, just a few.

How often should I be watering them?

Try to keep them moist; but not too wet. If the cup feels light in weight and the mix looks light in color, then give them a squirt of water. The Figs4 fun site has some good rooting info.

Here is a link that might be useful: Figs4Fun rooting