For me, a raw food diet for rabbits is simply cutting out pellets. Since everything else I feed Bandit just comes the way it's grown and cut (herbs, leafy greens, hay etc).
Free feed as much hay as wanted, and in terms of leafy greens, I'm not sure how much you'd want to feed, at least two or three packed cups a day for a smaller rabbit, more for medium and larger breeds. You would need to be feeding a large variety of greens, with at least 4 or 5 types every day, and rotate things in out and out on a daily basis. It's actually something I would probably discuss with a vet, since you want to make sure that you're giving them all the nutrients they need (and not overfeeding others), so you need to be feeding the right amounts, and the right variety.
As with any dietary changes for rabbits, progress slowly with one new food at a time.
Googling pellet-free diets might give you a good starting point too.