short answer: yes
details: if you and your dad are on a family plan, all you would have to do is dial *228 and enter 3. it will ask the phone number you want to activate on that phone so just dial your phone number. if you are having problems, just dial *611 and dial 0 and talk with the service rep and explain that you want to use your number on that phone.
if you guys each have your own account, your dad has to clear the ESN, call *611 and speak with a service rep. from there you just have to call *228 and enter 3
good luck
