I would think that you do different things for different parasites (i.e. mites, fleas, tick, lice, etc).
This are some potentially useful links Ear Mites,Ear Ailments,Alternative Therapies and Fleas from the Library. Hopefully something there will be useful until someone more knowledgable replies.
This might also get moved to the Infirmary, so if you can't find it, that's where its gone
it is very uncommon for domestic rabbits to get lice although it is common in wild rabbits.
You may be seeing fleas or mites or possibly a fungal infection. At any rate you cannot treat it without knowing what you are treating so it would be best to take the rabbit to a vet.
one word//.advantage..sold at farm animal supply stores/,i use the orange box.under9#/.read directions is a must!!..place behind head/on neck,..sincerely james waller