Windows Batch File Rename to Replace %20 Characters with _

I have a folder with a lot of files that I need to rename. The original format for example is ABC%20DEF%20GHI%20JKL.xyz. What I need to do is to replace each %20 with _. So essentially I'm parsing out the %20 characters from the file names and then replacing those with an underscore _ character.

Ideally I'd like to be able to complete this with a script rather than an application.