Google Adwords - How to cancel Automatic billing ?

I just open a new account and suddenly I read that : "Automatic payments Google will automatically charge you 30 days after your last automatic payment or when your balance reaches your billing threshold of $50.00, whichever comes first."

I do not want that they charge me automatically as I rarely use adwords ? How to change this ??

 

i think u must just edit the expiry date of your card.
that will ease you