Uninstall from Shopify admin like any other app. The storefront file is served by the app, so it stops when the app is gone.
Your products, pages, policies and sitemap.xml are not deleted by the uninstall. They were never edited by the file publish.
What remains
- In Shopify admin, open Settings or Apps
- Uninstall LLMs TXT
- The proxy URL will no longer serve the file
- Product and page content remain
If you reinstall later, publish a new task to create a fresh file. Questions can go to the contact page.