Is there any way to wipe Karma but keep achievements?

I am using this great plugin which works perfectly with the WP-Pro-Quiz.

Is there a “best practices” way to erase all the Karma points from each user?

I basically want a competition every month for smartest quizzer.
I want to have the same users battle it out anew, but I’d like them to be able to keep their achievements and I don’t want to edit each users Karma one-by-one.

Is there a best way to do this?

https://www.ads-software.com/plugins/achievements/