Yes, you will need to download the Turbo Card app or visit turbodebitcard.com in order to change your PIN. For security purposes, this should not be done over the phone. Here are the links for the iOS app and the Android app.
Remember, in addition to receiving your tax refund to the Turbo Visa Debit Card, you can also load money and activate the card for direct deposit through your employer. You can certainly keep both cards if you find that it's useful to have both.