To remove Bundle Builder completely, please navigate to:
Admin → Apps
Bundle Builder → 'Delete' option, in red text.
After Bundle Builder is uninstalled, the following will remain in your store:
The automatically created collection "Bundle builder products" containing all bundles
`templates/product.bundlebuilder.liquid` file (you can manually remove this by searching Bundle Builder in your theme liquid and remove it if you so desire, but this is not necessary to do as it won't affect your store in any way.)
Bundle products with associated variants (in Products section of your store)
When you've uninstalled the app you can delete the bundle products and collection from your admin.
It's recommended that you delete the bundle app before removing the bundle products.