It is very easy to upgrade from DoYourData Uninstaller Free to DoYourData Uninstaller Pro full version. First of all, you should get a license code. If you don't have the license code, please go to the Buy Now page to purchase a lifetime license code ($14.99). Then you can easily upgrade to DoYourData Uninstaller Pro version.
Step 1: Click the upgrade icon on the upper left of the interface. And it will pop up a small window of activation.
Step 2: Enter your license code and click on "Activate" button. Then it will upgrade to Pro full version.
If you have any question, feel free to contact us by sending an email to support@doyourdata.com.