Tomas Votruba has a tutorial posted to his site showing you how to update your Symfony application to make all of your services use auto-discovery rather than hard-coded configuration settings.

Do you use Symfony autodiscovery services registration everywhere and your configs have no extra lines? Skip this post and rather read another one.

But if you have many configs with manual service registration, tagging, and autowiring, keep reading. I'll show you how you can convert them easily be new Symplify package.

He starts off by talking about a few e-commerce projects he's been working with lately that define service configurations manually. He then mentions a package that's been created to help convert these over easily to autodiscovery rather than having to change them one by one. He provides the instructions to use this package and mentions some of the things that could go wrong in the conversion process to keep an eye out for.