You can port the two number to another carrier since they are not under contract - since the account are not setup with a primary line any more you can leave the last number on the account util the contract ends and then port it out with no extra fees. is you look at how the account is setup.. Verizon charges you for each phone you add the account you bill should go down in price roughly about 20 buck plus fees that you pay for each line. you could port the last device "c" but if you do it before the contract end you will occur a early term on that line also you might call customer service you might be able to decrease the number of mins that you pay for since you are going to only have one line on it just make sure that it will not renew the contract for that one line. make sure the customer service person clear states that and i would go as far as asking them to note the account.
*Sad face* Why do you want to port out two of your lines? Please let us know what we can do to change your mind.
In regards to the actual process of porting out two lines and only leaving 1 line active, TD_Rc is correct in the process. The only thing I would add is to make sure that we change your plan to a single line plan. Check out our plans here http://bit.ly/xdDajD .