Testicle tug-o-war.....

news.bbc.co.uk/2/hi/4253849.stm

How hard do you have to pull to pull off a testicle???? OMG!!! Ouch!!! I'm trying to imagine but HOW???? HOW????? How on earth do you pull one off?????? biting it off...cutting it off....but PULLING it off???????