So I have a small terrarium with mostly moss, but a few plants (most of which have died)

Today it has started to give off a mild (yet pungent) foot odor. I didn't know it was coming from it till I started to smell around that area. When I opened it up, I found that there is a white mold that has surfaced on the soil. Further inspection showed that the mold goes all the way down to the drainage rocks (as I can see it from the side).

What I am wondering is; Is there a way to clean this without removing the plants, or should I just chuck the contents and start over?