How to uninstall 3rd party extension

You need contact the extension developer to get instructions on how to remove the extension?
1. The instruction should provide the following information:
  1. How to revert back Database Table changes
  2. How to revert back Database Data changes
  3. Which files should be removed or reverted back
If it's a composer package, then modify the composer.json under repository and remove the package name by composer remove <package-name> command.
If it's a stand-alone extension, then remove the physical files from your repository (usually app/code/Vendor-name/Module-name
If config.php is commited, remove removed extension from config.php
Commit the changes
Ensure on your local Database that provided instructions are works.
Test on staging environment modules are disabled properly, the website works properly
Push to re-deploy
Only after it is tested and confirmed will you perform such changes on a Production environment.