For a mild infestation, dusting with DE (diatomaceous earth) can be effective. If you cannot find DE, you can also use mite dusting powder for chickens.
You will also need to do a thorough cleaning of the cage, j-feeder, water dish, and area adjacent to the cage, especially any wooden surfaces the rabbit has come in contact with ... fur mites can be introduced in hay as wild rabbits carry them and live in the hay pastures :x
Also, you will want to do a preventative dose on any rabbits "down stream" of the infected one, or any other rabbits handled after handling the infected one.
As the dust is not harmful, a preventative dusting of a doe just before kindling will not harm the kits.