Please be aware that the Power of Attorney is only effective while your dad is alive, not after he passes. After he passes, you will need to go through probate if he has assets left in just his name. As his agent, you should be able to withdraw or retitle the accounts now.
Many banks will give you a problem with the power of attorney and will want you to use their forms. If this happens, INSIST on speaking to a manager or the legal department and ultimately they will agree to allow you to use your form if it is in proper order.