2. (Optional) Remove the 1-line integration code from your theme which you added while setting up the app. The integration guides for badges and highlights are available here and here respectively. Keeping the code will not have any negative impact on your store.
3. (Optional) Delete the snippets/primeb.liquid file and snippets/primeh.liquid file from your Shopify Theme Editor. Do not delete these files if you have not removed the code mentioned in step3.
4. Uninstall the app from Shopify admin by clicking the Delete button.