How to go about selling my Verizon iPhone?

A few weeks ago I decided to go to the launch of the iPhone 5s and get a 32GB Verizon model. I paid the $30 upgrade fee and now it's on my cell phone bill. I recently decided it's not worth double the storage space for a fingerprint sensor, so I was wondering if it was possible to buy an iPhone 5 64GB on Verizon and add it to my plan and subtract the 5s and sell it on eBay or craigslist. Would this be possible? If so, what would need to be done before selling?

It is possible to sell the phone, just make sure to detach the phone from your account (and place an active phone in it's place). Just make sure to explain to the service rep that you intend on selling the iPhone 5S and that you will maintain the contract that you started on it.

If you decide to leave Verizon before completing your latest contract, or at least pay the ETF (up to $350), Verizon will blacklist the iPhone 5S you intend to sell (and if blacklisted after being sold, the phone will get shut off, leading to the buyer getting upset and having due cause to sue).