Please don't go, PETWRI43. What is your reason for wanting to leave?
You need to contact Customer Service at 800-922-0204 (or *611 from your cell phone) or visit your local Corporate VzW store to cancel a line of service. Be aware that VzW reps will try to talk you out of canceling, so be firm. Also, if the line is still under contract, you'll incur an Early Termination Fee and you'll have to pay off any remaining balance if there's a device agreement.
Verizon isn't going to contact you to lose a source of revenue, you have to contact them.
Is this because you need to save money or was this a line you don't need anymore? If it's for porting out to another carrier, that automatically disconnects the line on Verizon's end.
Verizon only accepts cancellations by calling their customer service line, or if you port your number out (which cancels your line/account with Verizon by design).