You should give the rabbits a place to sleep at night that is sealed off from the outside. Like a large box you can put them all in to sleep in at night. That way the raccoons can’t get them. Raccoons are just very sneaky and clever you can fix it up any way you want they will find a way to get in. but if you really don’t want to do that then you can practically rebuild the whole cage. Use a fencing material that has very small wholes like chicken wire. Dig a trench around were you wish to build the cage. Place large wood planks in the trenches. Attach the chicken wire to it and cover the planks up with dirt and larger rocks. Make the roof one continues sheet of chicken wire and cover the fencing with a roof or your chose. That should keep out raccoons and varmints. I hope this helps. :)
Ok I'm going to say it. Kill them. In time they will learn that area is not a place to be. I kill about anything I don't want around here. Even the annoying blue jays learned to shut up when they are around.