If your purchase or installation instructions tell you that you need to "Surrender" a license, please follow the steps shown in this iLok video:
If you have difficulties surrendering your old license, please return it to your iLok account using iLok License Manager software: drag and drop it from your computer or iLok USB key back to your iLok account, or deactivate it in your iLok Cloud Session. This will ensure a successful surrender.