So, you are using Thrive Theme Builder or Thrive Architect so far and want to switch to another WordPress theme. If this is true, then it’s quite easy as well complicated. See, changing theme is easy as you just need to go to Appearance >> Themes and Upload New Theme and Activate. Automatically Thrive will be deactivated from your website.
But all the design elements, beautifications you did using Thrive Theme Builder will be lost. Though you will not lose any content, rather your content will lose the visual design and become a simple bad content which you need to edit again as per your new WordPress theme design.
In case you deactivate the Thrive Architect plugin, then also you have to follow the same thing. You have to manually edit all the pages or posts that you have designed using Thrive Architect plugin. This is a very risky and tedious task and that’s why it’s not recommended for a large website with many content.