You can litter box train your rabbit as you do a cat.
Hay is highly recommended as the most foolproof method for litter box training. Simply put a layer of litter in the bottom of a large litter box and a bunch of hay on top of that. Rabbits will sit in the box and eat hay while they do their business. It’s very natural for them to graze and go at the same time so they usually take to it immediately. If this method is used, don’t put hay in any other place, this will only confuse your rabbit as to where he/she is supposed to go.
The safest litters are Yesterday’s News and Wood Stove Pellets, not only are these better for your rabbit, but they are odor free and highly absorbent. Do not use clumping cat litter, some rabbits like to eat litter and this will clump in their digestive tract if eaten. Whichever material you choose, make sure to change the litter box regularly to keep it clean. During training, you may want a slightly “dirty” litter box to help teach the rabbit where he/she is supposed to go. If you are constantly cleaning it, they’ll think that it’s suppose to stay clean and won’s use it.
Confine the rabbit to a small area (without carpeting is preferred) with the litter box. Don’t give them access to any other room until he/she is always urinating in the litter box. Stay in the training room for as long as possible to observe your rabbit’s behavior. If the rabbit has an accident outside of the box, wipe it up immediately with a paper towel and then place the rabbit in the litter box. This will teach the rabbit that the urine belongs IN THE BOX! If the rabbit deposits any droppings on the floor, immediately pick both the rabbit and the droppings up and put them into the litter box. Pet your bunny while he/she is sitting in the box. When the rabbit is using constantly using the litter box, you can then let them out into other rooms. Young bunnies and un-spayed/un-nuetered bunnies may be more difficult to train. Just be patient!