Hi! Are you familiar with the API explorer? You should take a look at the course service:

And then Courses > Batch course update

You can refer to my reply on this post 

For info on using CSV files to run things in the API. I haven’t tried it for this specific use case but that’s where I’d start :)

Agree with the above - you’ll only be able to do that using an API update as you can’t do mass course updates like that through the UI itself.