The title of this post is the exact search I found on Google recently that pointed to my site. It forwards to places that don't really answer this question.. so I thought I'd answer it quickly. script/generate migration will show you what files it generates in the console (and any generation script for that matter) so you can look through the list of files it generates and delete them manually. As far as I know, there is no reverse for this generator (or any generators for that matter) and you must manually remove the files it created one-by-one. I hope this answers the anonymous Googler's question (and you come back here to find the answer)!