@CynthiaEdwards1
It is possible with both methods (I've done both!)
Preferably, you would use a SIS import to do this if your courses have a SIS ID, with the courses.csv format and changing the 'account_id' to match the correct subaccount SIS ID.
You can follow these instructions -- please try it out in your BETA instance first before you do it in your live instance, just in case there are any issues.
1) Make sure your subaccount has a SIS ID (go to Settings in the subaccount and give it one if it doesn't have one)
2) Go to the account where these courses live -> go to Settings -> Reports tab, then generate a SIS export of Courses (this makes it super easy to get the correctly formatted file and also not accidentally change any other attributes of the course)
3) Delete any courses that you don't want to change and then change the 'account_id' to match the target subaccount SIS ID
4) Save and upload the SIS import.
If your courses DO NOT have a SIS ID, you'll need to use the API (update a course). If you need sample code for this in Python, let me know.