Quote Originally Posted by satomi325 View Post

2) Cervical Dislocation: Breaking the neck.
Put your rodent onto a flat surface, such as a table or counter. You can use something like screwdriver or stick to put behind it's neck. Push the rodent into the table with the screwdriver behind it's neck with one hand and hold onto it's tail with the other hand. Pull on the base of the tail until you feel/hear the vertebrae pop several times and the rat is dead. It takes like 2 seconds.

First one that popped up using the search box.