If you need to upgrade or downgrade your paid plan, you can do so by heading over to your billing management inside of the application. If you're already on a Pro plan, this page will look something like this:
In order to upgrade or downgrade, you need to click "Update Plan" in the Your current QuestionScout Pro Plan container. Clicking the Update Plan button will take you back to the plan configurator page with the sliders. You can drag the sliders where ever you want to upgrade or downgrade your plan.
Note that any changes to your plan, whether upgrade or downgrade are available immediately.