First, start the Scenes Editor application.  In the upper right corner there is a small square button containing a white question mark.  Click on it to open the following context menu.  Select Miscellaneous, then select Enter a DPLTRRL Number.

In the next window, click the Modify button to unlock the text box on the left.

Enter your limited time registered remote license number and click the OK button.

If you have correctly entered your number and it is still valid, you should see in the title bar of your Scenes Editor application, the suffix (In evaluation mode) be replaced by an expiration date.  Of course, an Internet connection is required at all times to validate this number.