How do you switch numbers between two phones?

i just got a green env but its on my dads number..he said i could have it..how do i switch my number onto his?How do you switch numbers between two phones?
call your cell phone company on a landline phone- not on your old or new cell phone. they will need to put the serial # from the new phone in the system so it matches up with your phone number. you will have to go through a reprogramming process over the phone with the customer svc person to get the new phone to work, then your old phone will go dead and you can donate it to Hopeline at any verizon wireless store so a victim of domestic violence can have a free phone.How do you switch numbers between two phones?
You'll have to either call Verizon, go into a store with the phone, or I think you can do it from My Account online (have to be signed in as the main account holder) on the Verizon website.