Really what they want is a way to narrow down candidates at the end of the day.
The unfortunate part is that these methods are often the things that actually prevent diverse workforces.
Recruiting from expensive ivy league schools rather than state schools guarantees that you end up with a similar ethnic and gender make-up as those schools.
It doesn't guarantee that you're getting more qualified or harder working candidates.
Usually something as simple as getting your recruiters to focus their efforts elsewhere is what will increase your company's diversity, without having to change any other aspect of your hiring process.