Tools are easy. You add it to the CI/CD pipeline, it fails if it doesn’t meet the guideline, people have to run the tool to get the merge in. On first run it’s painful, so if you’re not starting a project, use an autoformatter so it’s not all manual work. If you really want, you can even make your CI pipeline push commits with autofixes

Of course if you don’t have a CI pipeline that’s easy to integrate steps like this, you’ve got major issues to deal with elsewhere…