You simply have your license admin assign your paid subscription to your email address, and then when you login to the product again it should default to your paid version (unless your paid version is less than Universal Edition).  

In case your paid version is less than Universal Edition and for some reason you want to stop getting free usage of the Universal Edition that the trial offers, you simply go to the "Account Management" link at the top right-hand corner of PowerBuilder, and on the lower right-hand corner of the account management screen is a link you click on that will switch to your paid verison.

Hi Martin;

 If you cannot find the documentation, we'll be showing you how to do this later ths AM in the PB 2017 webinar !

Regards ... Chris