you can do it the same way i do rats/mice etc.

I just throw them in a plastic bag (the size of the ones from the supermarket) and hit it on a wall in my house and they instantly die.

Since rabbits are clearly much bigger you should use a trash bag and grip it real tight so that all the air is out of it and just give it a good wack (not too hard cause you may spatter brains everywhere) on a wall or on a pole and it will kill it instantly.

If you do it right the rabbit will die on the first hit if you do it wrong you'll givee the rabbit a headache lol..

But thats how i would do it to my rodents.

However once i start feeding my snakes rabbits they'll be alive.