1. Access the preferences pane.

    Keyboard shortcut: Command key (it has a ⌘ symbol) and then the ","

  2. Click the Trips Fields tab, to only show the fields that you have purchased, check the Show Only My Fields checkbox in the Visibility section. Unchecking show only my fields will require additional purchases to use the fields you do not own. For the fields you use, check the checkbox next to it. For the fields you don't use uncheck the checkbox next to it.